Feeling she needs to make one more friend before summer break starts, Bocchi attempts to befriend disciplinary committee member Kako Kurai, only to fail miserably. During summer break, the girls go to the pool, where Bocchi teaches Nako how to swim. When the girls go to karaoke afterwards, Bocchi comes across Kai, who is relieved to see that Bocchi has made some friends and remembers her promise to her. On the way home, Sotoka expresses her desire to become friends with Bocchi to the others.

After many hurdles, Bocchi manages to get on talking terms with Kako, only to learn that she has a policy against making any friends. The next day, as Bocchi helps Kako clean the classroom, Kako explains that her policy is to prove herself strong enough to live on her own. Meanwhile, Sotoka worries about asking to be Bocchi's friend while remaining as her apprentice. In the end, she decides to focus on her apprentice training to show her appreciation towards Bocchi.

During cooking class, Bocchi ends up having to work with an unfamiliar group of classmates. With some help from Aru, Bocchi manages to impress her group by making them some whipped cream for their pancakes. Afterwards, Bocchi works up the courage to introduce her friends to Kako before asking her to join her group for making curry during an outdoor class. After a successful curry, Kako acknowledges Bocchi's determination to become stronger and declares herself as her rival.

Strong Bocchi powers up! Today she's Super Strong Bocchi! And Sotoka becomes Super Strong Sotoka too! What's making her stronger than usual? ...Her shoe?? Natto?!

If she doesn't talk to all of her friends every day, they'll forget her! While Bocchi has more friends now, she has more worries too. What should she do to ensure she remains friends with everyone? Make her CD Debut?!

Finally... Finally... Bocchi has a smartphone! Now Bocchi can join the smartphone tap-tap group too. Yet first she takes her friend's advice and greets her phone. So when it responds and she asks it to be her friend...?