While shopping with Chitose at the local shopping arcade, Choco wins a free trip to the Hot Springs for 4. Choco chooses herself, Haruma, Chitose and Makoto to go. After a rehearsal bath at the public bath with Choco and Makoto, Makoto gets a call from her job while at the train station and she ends up not getting to go. Choco, Chitose and Haruma travel via train to the hot springs. When they got there they went to the baths. Haruma found out that it was a shared bath and he tried to hide from Choco and Chitose but after staying in too long he got up dizzy and as he was walking out Chitose saw his private places. That night Haruma couldn't sleep so Choco held his hand so he could.
商店街からの買い物帰りに立ち寄った福引所で、ちょこは千歳から福引券をもらって、見事、一等の家族温泉旅行を引き当てる。
家族4人で温泉に行けるということで、お兄ちゃんに加え千歳も一緒に行こうと誘うちょこ。
そこにちょうどよく現れた真琴も参加することになり、みんなで温泉に行くことに。
旅行当日、駅でお酒やおつまみを買いこんで電車に乗りこもうとした時、真琴の携帯に急な仕事の電話が飛び込んでくる・・・。
