Hotaro's history class is interrupted by an outburst coming from Eru's math class, prompting a discussion in the Classic Lit Club about the nature of the seven deadly sins, and what might provoke Eru to become angry.

One of Eru's acquaintances invites the Classic Lit Club to a screening of a student film made by the members of Class 2-F so they can offer their opinions. When the movie takes an unexpected turn, the club is called on to help find a solution.

When the others ask Hotaro about his solution to the murder mystery, he begins to have doubts about it himself. Hotaro confronts Irisu regarding the reason why she called the Classic Lit Club in to help finish the film.

Satoshi is ready for Jumoji to strike, but when the anticipated target is passed over, he must reconsider his strategy. Tomoe gives Hotaro a copy of "A Corpse By Evening," and Eru notices that the art style is similar to one she has seen elsewhere.

While in middle school, Satoshi rejected Mayaka's Valentine chocolate, so this year, she works even harder to present him with a Valentine's Day masterpiece. But when it turns up missing, the search is on to discover what happened to it.