Short stories included in Crimsons: Akai Koukaishatachi volumes. Volume 1 contains "Crimsons Gaiden: River Side Story" parts 1-3. Volume 2 contains "Crimsons Gaiden: River Side Story" parts 4-8. Volume 3 contains "Crimsons Gaiden: River Side Story" parts 9-11. Volume 4 contains "Crimsons Gaiden: River Side Story" parts 12-16.

| Namespace | Tags | | :- | :- | | parody | blue archive | | character | hanako urawa, hasumi hanekawa, sensei | | male | sole male | | female | beauty mark, big ass, big breasts, blowjob, halo, huge breasts, multimouth blowjob, multiple paizuri, nakadashi, paizuri, ponytail, school gym uniform, very long hair, wings, x-ray | | mixed | ffm threesome, group | [Source](https://e-hentai.org/g/2953366/39adfb7462/)

Vol. 1 - Ero Archive Vol. 2 - Zetsurin Taisai Vol. 3 - Zetsurin Taisai Kouyasai | Namespace | Tags | | :- | :- | | character | akane murokasa, ako amau, asuna ichinose, atsuko hakari, hanako urawa, haruka igusa, hasumi hanekawa, himari akeboshi, hina sorasaki, iori shiromi, iroha natsume, karin kakudate, kazusa kyouyama, mika misono, mutsuki asagi, noa ushio, nonomi izayoi, saori joumae, sensei, toki asuma, tsubaki kasuga, yuuka hayase | | female | big breasts, bikini, bunny girl, dark skin, eye-covering bang, glasses, gloves, halo, hood, impregnation, kemonomimi, lolicon, nakadashi, paizuri, pantyhose, ponytail, swimsuit, twintails | | other | goudoushi |

Shintaro and his school of salmon have been living in a small lake for generations. Tired of being muscled out of food by the bigger fish, they decide to make a bold move and head for the “ocean” that they’ve heard about in stories where it is vastly large and food is beyond plentiful. As Shintaro leads his school of salmon out into the sea, they soon realize how protected they were in the lake and realize how dangerous it is.