A spin-off prequel to a spin-off of mahjong manga Saki. Its elementary school part ends with a school trip. So in chapter 37, Onjouji Toki and Shimizudani Ryuuka visit Lake Biwa Museum, which has a large freshwater aquarium. The cylindrical tank exhibiting giant Lake Biwa catfish shattered in February 2023.
Posting about some of the manga I read. I read manga in Japanese.