Auf dem Schuldach trifft Riki die fröhliche, unbekümmerte Komari und beschließt, sie einzuladen, den Little Busters beizutreten. Währenddessen ist am Schwanz einer der herumstreunenden Katzen, um die Rin sich kümmert, eine mysteriöse Notiz befestigt.
On the school's roof, Riki finds Komari Kamikita, a clumsy girl from his class who loves sweets. Riki tells her he wants to recruit her for the baseball team, but he soon realizes that she may not be well suited for baseball. Later, Riki goes to find Rin after she shirks her classroom duties to play with several cats. One of the cats has two notes tied to it, the first of which says that there is a secret to the world and if they want to find out what it is, they have to complete several tasks first. The second note lists their first task: Fix the sanitation problem in the boys' dorm storage shack. Riki doubts the sincerity of the notes, but Rin is excited to take on the first task. She later gathers up Kyousuke, Riki and Masato to go clean the storage shack. Komari finds them there and agrees to be join their baseball team, but first she and the others go to work cleaning up the shack. On the baseball field, Komari displays a complete lack of athletic ability, but Kyousuke still welcomes her onto the team after she replies to his question of what is necessary for baseball with the answer, "Guts, bravery and friendship." Soon after, Riki collapses from an attack of narcolepsy, which he has had since childhood.
理樹は屋上でこっそりお菓子を食べていたクラスメイトの小毬に出会う。
前向きでのんびりした性格の小毬と親しくなった理樹は、彼女に野球チームのメンバー集めをしていることを話してみる。
あまり野球に興味がなさそうな小毬だったが、恭介の入団テストを受けることに……。
一方、いつものように猫をかわいがっていた鈴は、その中の一匹のしっぽに巻きついた手紙を発見。
そこには不思議なメッセージが書かれていた。
리키는 옥상에서 과자를 몰래 먹고 있었던 같은 반 친구 코마리와 마주친다.
긍정적이고 느긋한 성격의 코마리와 친해진 리키는 그녀에게 야구팀 리틀 버스터즈에 들어오지 않겠냐며 제안하는데...
별로 야구에 흥미가 없어 보이는 코마리지만 일단 입단 테스트를 치루어 보기로 한다.
理树在房顶上见到了在吃零食的同班同学小毬。理树对小毬说了正在召集成员的事情。看上去对棒球不怎么感兴趣的小毬，居然接受了恭介的入团测试……另一边，依旧和平时一样在和猫玩耍的铃，在其中一只猫的尾巴上发现了一张纸条。在纸上写着不可思议的信息……
