Kujira no Kora wa Sajō ni Manabu (クジラの子らは砂上に学ぶ, lit. Whale Calves Learn on the Sand) is a spinoff 4-koma series of Children of the Whales. It is drawn by Ebi Umeda, Abi Umeda's sister, and it began serialization April 6, 2018.
A preview image of the series
Plot
It is a comedic spinoff taking place in a modern-day school, similar to the OVAs.