Under the tutelage of the great demon warlock Romberg, Ike grew up with knowledge regarding an ancient advanced civilization that once ruled the land. Coupled with his innate talent in magical arts, this upbringing allows Ike to quickly rise in the Demon Lord's army ranks, leading his brigade to consecutive victories against humans. However, Ike has a secret—he is a human himself. Despite knowing all too well the consequences if this information is ever to leak, Ike is willing to face such immense danger to achieve his goal: find a way for humans and demons to coexist and stop the war that has been carried on for far too long.

Hana lives on the small island of Tonakijima, with a population of 600, and loves reading to the island's children. Mizuki, the president of the school's broadcasting club, notices Hana's talent for engaging others through her storytelling and invites her to join the club. As Hana embarks on this new journey, she experiences many "firsts" with the broadcasting club members, deepening her love for reading even more.

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.

Tanya Degurechaff is a soldier who has the appearance of an innocent young girl. But behind her cute facade lies the soul of a ruthless salaryman who challenged "Being X"—the self-proclaimed God who reincarnated the man into an industrial world of magic. By doing this, Being X hopes to prove that, if the situation were dire enough, even a non-believer like this man would pray for God's help. Opposing Being X's desires to make her suffer, Tanya enlists in the military with the hope of living a peaceful life. She manages to impress the higher-ups with her aptitude for war, swiftly rising through the ranks. However, her country soon participates in the ongoing world war, quickly crushing her dream. In an attempt to return to her calm she starts using any merciless means to obliterate her opponents. Thus begins the saga of Tanya the Evil and the Empire as they seek world domination.