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: The group pays a visit to Sakaki's older sister Miiko's Cake Shop, the Hatch Potch, where Io and Sakaki work.
Part A: The winter is almost over. The gang divide themselves into two teams and play snowball but Mayoi and Sakaki have some tricks up their sleeves.
Part A: Due to a teachers' meeting, afternoon club activities have been cancelled, so Mayoi announces a "Kick the Can" game, for which the students are divided into two teams: hiders and seekers with a special penality for the losing team.
Part A: After the five have discussed some embarrassing details of the physical check-up, they settle on a competitive volleyball match. The losing team has to fight for the most popular lunch items in the school cafeteria.
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.
Although summer homework is still waiting for them to finish, except for Io, the five decide to take a train trip to a mountain resort. In the Drift race, they race to the mountain resort, and race along the mountain in a parody of Initial D.
Part A: The girls decide to pay a visit to Io's place as Tsumiki's air conditioner is broken. However, Mayoi and Sakaki are still held by the task of finishing up their homework, and urges the others to not worry about them and have some fun by themselves, despite their behavior says otherwise.
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 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 A: It's valentine's day and the girls decide to make some chocolates, at school Tsumiki forgot the chocolates she wanted to give to Io. Everybody was having fun trading chocolates except Tsumiki. After school, Tsumiki runs back to her house to get the chocolate, but on the way back the chocolates got wet and then Io arrives with his umbrella to protect Tsumiki from the rain. Even when the chocolates were all wet, Io still accepted the chocolates.