Grand Blue Season 4 Anime Details and Episodes The fourth season of Grand Blue. Series info Watch free DetailsStatusUpcomingSourceMangaCountryJapan GenresComedySlice of LifeSports RelatedGrand Blue (Source)Grand Blue Season 3 (Prequel) CharactersChisa KotegawaIori KitaharaAina YoshiwaraSakurako Busujima (Supporting)