Written and composed by Kuwata himself, "Manatsu no Kajitsu" was one of the songs on the soundtrack album, "Inamura Jane"（稲村ジェーン） from the movie of the same name which was Kuwata's first foray into directing. The movie itself was a coming-of-age flick which took place at Cape Inamura-ga-saki on the popular shores of Shonan in Kamakura City.
The song peaked at No. 4 on the Oricon charts after its July 1990 release and became the 9th-ranked song of the year. It also won a number of awards, including a Japan Record Award in the Pops/Rock category. Kuwata admitted that he had wanted the song to get the Grand Prize but the anime song "Odoru Ponpokorin"（おどるポンポコリン） beat him to it. No word on whether Kuwata threw a rock into the television when "Chibi Maruko-chan"came on. As for the album, it was released in September 1990 and hit the top spot on the album charts. It ended up being the 2nd-ranked album for the year.