Hyouka

"Energy conservationist" Hotaro Oreki joins the Classic Lit Club at his high school at his sister's behest, to keep it from being shut down. Also joining the club are his best friend, Satoshi Fukube, and Eru Chitanda, a curious girl who enjoys mysteries.

Eru grows bored of the club's lack of activities, and suggests that they prepare an anthology to submit for the school's culture festival in the fall. While tracking down previous anthologies, the club discovers a mystery in the school's library.

Over coffee, Eru opens up to Oreki to explain why she joined the club, and asks him for his help with a personal matter. Still unable to locate any anthologies, the club members run into an obstacle when trying to search the club's previous room.

Eru decides to solicit Satoshi and Mayaka's help hypothesizing what happened to her uncle. The club members meet at the Chitanda estate, where they present their research and surmise what they believe happened 45 years ago.

Hotaro is torn between continuing with his "gray" life and the "rosy" life that the others live. A phone call from Hotaro's sister leads him to believe that there are pieces missing to his theory regarding the events of Sekitani's expulsion.

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.

During summer vacation, the Classic Lit Club members take a trip into the mountains to stay at a hot springs resort inn run by Mayaka's relatives. While there, Eru and Mayaka see what appears to be the ghost of a man who hanged himself!

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.

In search of a conclusion to their movie, the assistant director, the prop master, and the publicist meet with the Classic Lit Club members one at a time to propose their solutions to the unfinished murder mystery.

After meeting with Irisu, Hotaro has a change of heart, and sets his mind to solving the murder mystery. Hotaro and Satoshi discuss the nature of their own potential, and what each of them might be able to accomplish.

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.

Hotaro's sister returns home, and sets her lethargic brother up with a temporary job filling in as a lifeguard at the city pool. Satoshi invites Eru and Mayaka out to see Hotaro at work, and the group stumble upon a minor mystery to be solved.