The science lessons are short "omake" bonus features originally present on the first two volumes. Each short lasts around two minutes, and stars super deformed versions of Noriko, Kazumi and the Coach explaining the various scientific aspects of the series. (Source: Wikipedia)

Tokimeki Memorial brings together the twelve young girls from Kirameki High School, but revolves around the main girl, Fujisaki Shiori. The story starts at the beginning of the third school year, which is the last year before the main character can choose a girl and date her at the graduation.

In the past Mutsumi (Mucchan) and Sae (Sacchan) met. Enjoying the time together, they decided to meet again and chose a place. Mucchan, however, never came to that place. A few years later he passed through that place on his way to school, and met Sacchan, who had been waiting for him for all those years. And so, they start playing together again. However, it won't last so long, because...

A series of shorts parodying the main series Prism Ark.