Not much is known for JianHao in the early life. What's known is that he's born from the Tan family from Sylvia Tan and an Edmund Tan, living with his maternal grandfather Gong Gong, JianHao respected him so much he named his pet crocodile after him. He has two siblings: Nicole and Zhi Kai. JianHao grew up to be a rather rebellious, but creative boy with preference to think outside the box. His mother has expectations that he would be able to succeed her family business that she headed, but JianHao was rather unlucky academically, mostly because one of his habits is heavy procrastinating.

During his kindergarten days, he used to be classmates with Sandeep.

Throughout Season 1, JianHao established himself as one of the bad boys of the school, prone to breaking rules, bullying his teammates, although he's also not that averse to protect his friends from danger, though sometimes to an extreme; he saw the popular student Ben as a bad influence for his sister Nicole and thus went out of his way to prevent them from flirting.

He didn't have good opinions for the teacher at the time: Mr. Muthu Raja, as while strict and only doing his job, he's often times mean and controlling at him. It's only after somehow Mr. Muthu Raja revealed himself to be a gamer and bonded together with JianHao over MapleStory M that JianHao seemed to agree to be more obedient and supportive with Mr. Muthu Raja's teaching. Alas, the moment was only fleeting; the next day, Mr. Muthu Raja was fired and in his place was the extremely fierce, borderline sadistic Madam Soot Beng that continued to give him trouble.

In the season's exam, JianHao, as usual, got distracted and procrastinated until he became desperate and prayed for God to let him pass the exam, or failing that, hoping that the exam will be cancelled by a meteor destroying the school. Obviously, that didn't work, and JianHao was only able to squeeze out the mark 49.5.

He spends the last moments season holding a party in his house, where he accidentally caused his otherwise purdy and diligent friend Denise to get drunk and had a complete contrasting personality.

To JianHao's annoyance, aside of his embarrassing mother, he's once again stuck in Class T1T5 with some of the friends he considered 'lame' (but they would end up being his closest friends later): Vincent, Ren Yi Xiang and Kevin. And Madam Soot Beng continued to haunt them as their homeroom teacher instead of taking a maternity leave. Regardless, JianHao proclaims himself a changed man and decided to partner with Denise, the top student of the class, to fix his grades. However, JianHao ended up learning that most likely as an effect of getting drunk in the party he held, Denise has taken turns into rebelliousness and didn't want to be the good star student that she was before.

Our hero on the picture day.

At first, JianHao went along with her rebellious phase, until the picture day where he learned that she's in danger of being expelled due to her new personality. He approached and comforted her, gave her a pep talk that she should be more proud of her true self, ending with the phrase "It's my turn to take the photo now." To facilitate that, he sabotaged his own photo-shoot during the Picture Day, enraging the photographer Mr. Lakosh. This gave Denise time to revert back to her old personality and ending the Picture Day happily, exactly what JianHao banked on.

At this point, JianHao is practically friends with Denise and she's thankful for what he has done to him. However, his journey to be friends with Denise isn't as smooth as he would thought for one thing: His best friend Vincent also had his eyes on Denise. They competed for Denise's affection while JianHao also dealt with the everyday school life problems.

Until the day for Group Project. JianHao was stuck with less than familiar teammates (Trev, Sandeep and Vicknesh) while Vincent ended up being in the same team as Denise. JianHao got desperate in trying to pass the group project so he proposed with the idea of paying someone to do the project for his group. However, he encountered Denise outside and she confessed about the type of men she didn't like: Those who cheated on their jobs with no sense of integrity. JianHao became reluctant to do his plot, but he's already in too deep with his team. Denise ended up finding out JianHao's cheating and lost her respect on him, with the love triangle now swinging on Vincent's favor, and JianHao is frustrated at himself for losing Denise's trust.

Though at the very least, one of his biggest problems would soon be lifted, in a way: A new teacher, Miss Sherly, was admitted to Titan Academy and she's much more personable than Madam Soot Beng, who would confiscate JianHao's phone eventually. When Madam Soot Beng proposed a quiz, JianHao spotted a set of cheat sheets and decided to spread it to the class. Unbeknownst to JianHao, Miss Sherly caught wind of this and decided to report this to Miss Siti, threatening to get him expelled since she actually saw no hope on JianHao. Madam Soot Beng, however, decided to take the blame and said she's the one who provided the cheat sheets in the first place, thus getting herself fired. JianHao and Madam Soot Beng exchanged cordial farewells during her last days. However, JianHao forgot to ask his confiscated phone back, something he would regret later.

During the exam, JianHao got his revenge on at least Sandeep for pressuring him to cheat and losing Denise's trust by forcing him to take his own cheat sheets and get exposed by Miss Sherly. He also starts noticing on how toxic Vincent can be against Denise, borrowing her calculator and not returning it to the point she's not confident on her exam results and crying as a result. Unfortunately for JianHao, for this exam, he once again got 49.5, his mother would be disappointed especially after he was promised some new items in case he passed (that she ended up having to bribe Miss Sherly to 'fix' it).

But then a new threat presented himself: A mysterious new student named Terry who somehow was a match of Denise in terms of brains. Denise naturally flocked onto him, and it was less likely for JianHao to intervene. After sorting out his grade problems, he and Vincent witnessed Terry exiting the girls' changing room while holding a phone and a smirk planted on his face. At that point, love triangle would have to wait, JianHao and Vincent teamed up to gather some friends to expose Terry to Denise. Unfortunately, they were outsmarted by Terry while Denise's current distrust on both of them didn't help things.

In an attempt to stop Denise from studying in Terry's house, JianHao accidentally invited everyone into his house for doing home work, which proved to be his chance to redeem himself for Denise. He had to juggle between keeping an eye on Terry, proving himself to Denise and avoiding the wrath of his mother in case chaos erupted. Some juniors also ended up being invited due to his influencer friend Jasmine, and they asked if there was a pool party. At first, Jianhao was interested, but then he saw Denise looking at him disapprovingly, and he somehow managed to turn his problems around by telling his juniors that there will be no pool party, they're only here to study and do their home works, which eventually impressed Denise that they could start mending their relations again. Some chaos did occur such as some vase breaking and his pet crocodile getting loose, but Jianhao avoided his mother's wrath in general.

He finally managed to fix his relationship with Denise for good during the class' visit to the library over the fact that they're both Star Wars fans, but Terry's efforts to win over Denise is stronger that he resorted to hypnosis to make Denise kiss him. Once again JianHao teamed up with Vincent to interrupt and in this case, made a backup plan by contacting Jasmine to record Terry's actions. The plan succeeded, but exposure would have to wait because Denise's mind was muddied due to the hypnosis and Jasmine demanded extra efforts to even get her to give the recorded video, which is something JianHao didn't foresee.

In this season, a new class is open, and his youngest brother Zhi Kai starts enrolling in the Titan Academy as well. And amongst the freshmen, a fanboy of JianHao, Sunny, is included. The moment lasted only temporarily as the pandemic hit in and this caused Class T1T5 to be required to study at home. But it was during this time that JianHao managed to see Terry getting exposed as a closet pervert during an online class session where he's cornered to reveal his computer screen when he's doing a photoshopped image of him being the harem lord with Denise as one of its members (without JianHao even lifting a finger), so that's one less threat he had to deal with when it comes to Denise.

Shortly after, Class T1T5 is mandated to return. When JianHao returned to school, he's once again on the good graces of Denise, but he's shocked that Miss Sherly would announce her departure. Having grown more accustomed to her, JianHao was upset, but he's more concerned to the even more depressed Vincent who didn't take Miss Sherly's departure well. To his surprise, Miss Sherly's departure was temporary. To his bigger surprise, it seems that the love triangle between him, Denise and Vincent is back to square one, since Denise holds both of them on equal level of affection.

At Season 4, dark clouds start to loom to the Academy which will affect JianHao's mindset and efforts further than 'improve himself to impress Denise'.

After one particular chaotic lunch break, the new team of board of directors under The Organization, Alan and Regna, showed themselves and they absolutely had no time to cater with the students' hijinks. After the pandemic, the Titan Academy was facing a financial crisis that Miss Siti had no choice but to sign a deal to the Organization that Alan and Regna belonged to in order to make sure the students will have a place to study. However, both Alan and Regna demanded to impose extremely harsh and rigid rules with the threat of expulsion for those who failed their expectations, and due to the school lunch chaos, the two classes are punished of cleaning all classes and canteen as a small showing of how disproportionate they can be.

While cleaning his class, JianHao came across one of his juniors, Cleverly, having been called by both Alan and Regna who took interest in his project. Because of this, Cleverly tried to defend the two saying it was just a misunderstanding, in which JianHao didn't buy it. However, they learn that the two are coming to observe the class' cleaning progress, so JianHao, who was assigned into another class, hid under the table, only to hear the evil plans that Alan and Regna had in store for the students and Cleverly's project. They're almost found out, but Cleverly exposed only himself, sacrificing himself so JianHao and a few witnesses still carry the information.

JianHao tries to tell the information he got towards at least Denise and Vincent, but he didn't get very far. He does, however, witness what happened to Cleverly: He got shaved completely bald and then was expelled.

Further complicating things is that somehow, Madam Soot Beng returned as Class T1T5's homeroom teacher and is still as fierce as ever, as if taking the side of the Organization's extreme rules and making it worse. JianHao, however, has yet to realize that Madam Soot Beng actually meant well this time, she was supposed to be an ally of the students against the Organization.

For once, luck sided with JianHao a little that he managed to pass the exam this time with the score of 51. However, the Organization's interference causes a majority of his class and his junior class expelled, just as he tried to warn both Denise and Vincent, and JianHao is left with a majority of his friends no longer with him. Thankfully for him, Denise, Vincent and two of the Class N4T1 students present with him during Cleverly's sacrifice, Chloe and Diana, avoided expulsions, and JianHao knew something had to be done...

But his luck was reversed as he found out that his new class, T1-T6, are full of strangers that doesn't share his sentiments and he felt stranded in a new world, where Denise has committed herself for now to Class T1-T1 and partnering with Terry out of obligations. After talking with Kevin, JianHao gets an idea of trying to discover another universe where Class T1T5 never disbanded. He found his answers with Dr. Burqq, who somehow doubles as a multiversal magician, and he's brought to another universe. JianHao is pretty sure that his luck will turn around in this better universe... But against his expectations, everyone he knows of has taken different roles that he does not recognize everyone. At first, JianHao begins to doubt that his presence in the other universe is ruining everything. But he is tempted to stay anyway after a little general pep talk with his counterpart from that universe, after all, nothing could go wrong in a universe where the Organization never sank their claws into the Titan Academy, right?

Until he discovered that in that universe, he's the son of Madam Soot Beng. And that was the last straw for JianHao to beg for Dr. Burqq to send him back home, he'd rather take on the troubles in his main-verse than dealing with Madam Soot Beng as a mother (even if she's actually less strict and supportive there).

Returning from his multiverse hijinx and at least inspired not to give up on his friends, JianHao gathered some of his remaining friends, including Vincent, Kevin, Sunny, Diana and Chloe, the last one apparently transferred out despite passing the exam (and also Maddy, whom Vincent brought for tag-along), for one purpose: Perform a school heist to steal the exam papers of those who failed and then shred those papers and change the official results of the exam, so the Organization had no choice but to re-admit the expelled students. After some slight difficulties, JianHao manages to obtain the item he wanted and eluded the security guard Uncle Salim with the help of Madam Soot Beng, which surprises JianHao as he knew her as the sadist anti-student teacher. However, Regna manages to catch on them, but they still manage to escape thanks to the sacrifice of Cherylene. With all those out of the way, JianHao's plan is a success and the Organization ends up conceding to re-admit the expelled students, although Alan has stated he's not done with his plans to lord over the Titan Academy.

Things might seem to return to more normal as Class T1T5 returned once again, but JianHao still mourned for the loss of Cherylene, even if she was formerly a highly annoying, shrill yet OK student, she was still his friend and classmate, and last he heard, she had it worse than Cleverly; if Diana's claims were true, then Cherylene would be blacklisted in all educational platforms in Singapore, preventing her to even go to boarding schools like Cleverly. Life would at least return normal for Class T1T5 because of her sacrifice, though JianHao knows that the battle is not over.

During a boat trip with the class, the whole class ends up being stranded in an island. JianHao tries his best to motivate and lead his team to survive the trek, but in the same time, he manages to find time to share a moment with Denise, not only tightening their bonds, but he also seems to have finally prevailed in his love triangle against Vincent.

With him and Denise being a couple now, JianHao has been helping her with things she's not good at and she returns them in kind. However, during the science class, he ends up accidentally burning the whole school thanks to Vincent's carelessness and Terry's plot. He and Vincent take the blame and end up being punished by being made into assistants of the Night School classes. JianHao is at first aghast about it, but seeing the quirkiness of the Night School class members and the chance to boss Mr. Dan around officially, he lightens up on it. He does, however, lament about how he will not be able to date Denise in the meantime.