When Isaac gets a bad grade again, he wishes for a way to get better at science. This wish creates Totto, a science-loving bunny with strange powers. Isaac must come to terms with the fact that only he can see, hear, and talk to Totto. But when he becomes a cell to get a better understanding of what goes on deep in our human body, Isaac knows Totto is a secret he must keep.

Isaac is still trying to get used to Totto’s constant presence and expects Totto to give him all the answers in class... but Totto refuses. Then there’s a blackout in class! Totto takes Isaac into the circuitry to make him understand why the faulty computer caused the electricity to trip in class. Rubina grows suspicious of Issac, as not only is he getting better in science, she also finds him talking to himself...

The hottest day of the year seems to be here – just in time for the school’s Frisbee competition. Abby, who is Issac’s best friend, wonders if there’s a way to escape the heat… by making rain or rather, water bombs, just to skip the competition! At the same time, Totto takes Issac beyond the clouds to show him how rain is formed.

Isaac’s worst nightmare has come true: he is stuck in the lift with of all persons, his arch-rival, Rubina, who screams her head off! She is claustrophobic and forces Isaac to keep mum about her fears, but Isaac realizes there is a lot more that Rubina is hiding…

The annual school play is coming up, and all the kids are excited to take part. However, when Rubina doesn’t get the role she wants, she decides to sabotage Isaac who is selected to be the costume designer instead of her. Can Isaac and Totto stop her in time so the show can go on? Or will he earn the wrath of the two leads of the show: Abby, and Rubina’s best friend Adrian?

Isaac dreams of being a superhero all the time, and he wonders if there is a way for him to help people. At the same time, Rubina suspects Isaac is cheating during exams, and sets up a trap by using her friend Lisa as a pawn to prove it.

Isaac and Totto must take care of the class orchid…but they learn things the hard way because of Issac’s rash decision! The orchid starts to wilt. Issac and Abby are in big trouble if they do not get their act together fast enough to save the orchid from wilting further...

Rubina’s favourite necklace has gone missing and to her disdain, Isaac decides to help her! He believes using a magnet would get the job done, but he might not only uncover the necklace he is looking for but also unravel the most precious secret Rubina has guarded all this while…

When Isaac’s father experiences a health scare, the Ng family decides to re-evaluate their diet. Isaac finds it tough to adjust, but he realizes how important diet is when he discovers his classmate Adrian’s very own health problem.

In a bid to get Dr. Ng’s anger management problems under control, the Ng family heads to an art café to de-stress. But things get out of hand when Dr. Ng becomes obsessed with making angry red paintings! Can Isaac find a way to help him express himself or will it just strain their relationship further? Will Totto be able to help them work out their differences?

It is Abby’s self-declared Vegan Day and everybody brings a vegan dish they like to show off. Isaac has made vegetarian curry but it turns cold when he gets to school. Without any way to heat it up, the cold curry might just land Isaac in hot soup! Ms Rani, their science teacher, is the first victim of Issac’s folly.

The class takes a field trip to a big slide in a park, where Isaac must now confront his own fear of heights. Rubina discovers this secret, but unlike Isaac, she is not afraid to tell everyone what she knows. The drama begins to cause a rift between Isaac and Totto as Issac gains his self-confidence and decides not to heed Totto’s advice.

Isaac and Totto’s friendship enter a dark period. They have a falling out, and the best friends will not talk anymore. Isaac’s overconfidence eclipses his ability to be sensitive to others like before. He invents binoculars to watch the lunar eclipse and decides to charge his classmates for the use of his inventions, creating new problems for him. Can Totto help him or will Isaac fall further into a world of self-deceit and distance himself f...

When an insect infestation breaks out in school, Isaac believes his new special insect repellant can help. But his invention backfires and creates an environmental catastrophe in school! Ms Rani and his classmates are furious! Isaac must make amends with Totto in order to fix this very “bug” problem soon or he might just get into hot soup again with the school!

Mrs. Ng falls sick, so Isaac and Dr. Ng must take over the housework and running of the antiques shop. But both of them have hardly done it before! Can they find a way to juggle these responsibilities? Will this arrangement strain their relationship further or will it pave the way to an amicable compromise?

The day of the Great Singapore Invention Fair has arrived! As Isaac unveils his newest invention against his father’s wishes, Mrs Ng is torn between supporting her son and not hurting her husband. In the meantime, Sir Fong returns and tells Isaac that his creation may not be good for society. Isaac is terribly discouraged. Will Totto come to his friend’s rescue and show him the right way? Could the solution to this problem be... in the future...