One cold day in winter, Miniwa Tsumiki joins her close friend and crush Otonashi Io to a visit on the Arcade along their friends Katase Mayoi, Haruno Hime and Inui Sakaki.

Part A: It's time for summer uniforms and the students are assigned to clean the swimming pool. It does not take long for them to make a mess of it.

Part B: The afternoon before the test, Mayoi suggests a study group meeting in Io's house. Sakaki cannot go because he has a shift in Hatch Potch, so it is Io and the three girls. After the test, the weather turns rainy and there are not enough umbrellas.

The time comes for the school festival and the five decide to mount a crêpe stand (named "Tsutsumin!" meaning something like "I wrapped") together, which turns out to be a great success. Io serves as the cook but also sews Tsumiki's mascot uniform by hand, and promises the first crêpe to her. Mayoi wears no lab coat over her waitress uniform.

Part A: Mayoi buys a bear costume for cheap and decides to put it to use by scaring as many people as she can.

Part B: Mayoi is planning to have a party on Christmas Eve but has to put it off to Christmas Day as Hime and Io promised to work in Hatch Potch. She and Tsumiki also stand in to help Io sell Christmas cakes in front of the shop.

Part A: The five go to the New Year's festival. The following day, they come together at the Inuis' place where their teacher Kikue Sakuragawa, who seems to be Miiko's friend, is also present. They talk about new year's resolutions, play games, and have a meal.

Part B: It's a very cold day. Due to a flu epidemic, more than half the class is absent, school finishes after lunch. Tsumiki and Io appear to have a 'moment' which leaves Io rather confused and flustered.