During a rainy day, a woman comes across a strange animal waiting by the side of the road. Pleading to be taken in, the creature offers the woman an umbrella in an attempt to show off its appeal. Intrigued by its clever nature, she brings the dog-like creature home and thus begins their life together.

Renji Kusakabe, an arcade employee, one day notices a small foreign girl struggling to win a stuffed toy called "Manly Koala" from a crane game. Three hours later, after finishing his shift, Renji sees the girl still at the game, but the toy remains unmoved. Feeling sorry for her, he decides to help. He inserts a 100-yen coin and, with one skillful try, wins the toy, which he then hands to the girl. Startled by this unexpected gesture, the girl looks at Renji with suspicion. Flustered, Renji hastily tells her it's a Valentine's Day gift. Little does he know, in her home country of England, Valentine's Day is traditionally when men give women gifts along with a confession of love.

Alicia, who had dreamed of becoming a hero since childhood, is chosen by the king as one of the thirteen heroes. Armed with a legendary sword, the heroes set out to defeat the Demon King Clevatess. However, their recklessness triggers a terrible crisis that could wipe out all of humanity on the continent of Edsea. Now, the world's only hope lies with a baby entrusted to the Demon King.

Yuu Yuutani, a first-year high school student with sharp eyes, large piercings, and flashy two-tone hair, is not a well-known bad girl who everyone makes way for. She is actually a very good girl at heart, and her mind is always full of thoughts of the school's Madonna, Atori Mizutori. Wanting to attract the attention of the disciplinary committee chairman Atori, Yuu decides to quit being an honor student and become a "bad delinquent!" A school comedy depicting the struggles of a slightly foolish self-proclaimed delinquent is about to begin!