Such violence in a slice of life manga!?
Hikari is snorkeling not far from shore when she spots a tomboyish elementary school girl underwater looking at a hole between the rocks. Hikari goes to investigate the hole and waves the girl over to look at an octopus guarding her eggs. After surfacing, Hikari finds out the girl is a local, but the girl refuses to tell Hikari her name. Hikari explains that the octopus mother will guard her eggs day and night, during which she will not leave the nest or feed, and the young girl is impressed by these facts.
A week later, Hikari finds the young girl again in the sea and can tell that the girl can't find the octopus nest by herself. In exchange for Hikari's help, the girl reveals her name to be Kokoro (not 100% sure of the name since I'm reading Chinese scans). The two dive underwater and they spot an eel approaching the nest. Kokoro tries to stop the eel but she gets scared. As the eel approach the nest, the octopus comes out and starts fighting with the eel and the fight carries off into the distance. Kokoro spends the rest of the day waiting at the nest site and eventually the octopus mom returns to Kokoro's relief.
Some day after, Kokoro returns to the sea with a wet suit. She and Hikari spot an eel again. Kokoro tries to throw rocks at the eel to no avail, but Hikari just swims in front of eel and the eel retreats. Hikari and Kokoro then go to check out the nest but the octopus is missing. Kokoro is sad that the octopus is gone and wants to look for the octopus, but Hikari stops her and explains that the octopus mom typically dies after guarding her eggs. The important thing however is that the eggs are still alright, and Hikari invites Kokoro back to her grandma's diving shop for some soup.
This month we have a chapter about sea life and features a new character. We got to see a pretty amusing octopus vs eel fight, and Hikari shows off her infectious charm once again, winning over yet another person she met. I knew about the octopus' habit of guarding their eggs already, but it was good that the little nature lesson was included in the chapter. Meeting random, interesting characters is a staple for slice-of-life mangas, and we'll see if Kokoro will become a recurring character. Given Kokoro is younger though, we probably won't see her that often since she's too young to be in the diving club.