GAKUEN UTOPIA MANABI STRAIGHT! SPECIAL

This episode takes place between episodes six and seven from the regular broadcast. Manami and her friends raise money for a trip during summer vacation, but when on the day they go, a storm blows through, and they have to cancel their plans. Instead, they stay in a local hotel in a rural area overnight and go back to their town the following day. — Description from AniList community (anilist.co).