失踪していた父・五郎（高橋克実）が、謎の少年（齋藤潤）と共に帰ってきた。経営難のおおば湯をなんとかするために全国の銭湯を巡ってヒントを探していた五郎は、旅先で出会った銭湯に興味があるという少年をおおば湯で働かせたいと思い、連れて帰ってきたのだという。
五郎のマイペースさに苛立ちながらも、少年を迎え入れる七苗（川口春奈）たち。
しかしその少年は何か訳ありの様子で、頑なに心を閉ざしていた。
そんな中、五郎は七苗たちが進める「おおば湯リニューアル計画」に難色を示して･･･。
His missing father, Goro (Katsumi Takahashi), has returned with a mysterious boy (Jun Saito). Goro, who was looking for hints by visiting public baths all over the country in order to do something about the troubled Obayu, wanted to work at Obayu because he wanted to work at the public bathhouse he met on his travels, so he brought him back. While being irritated by Goro's own pace, Nanae (Haruna Kawaguchi) welcomes the boy. However, the boy seemed to have some reason and stubbornly closed his heart. Meanwhile, Goro is reluctant to accept the "Obayu Renewal Plan" promoted by Nanae and others.
