Mike (Agent 8) has finally got used to life up on the surface. Alongside with his girlfriend and best friend in one, Sarah (Agent 3), he feels like he can overcome any challenge or obstacle for her sake. After a series of unfortunate events, it's up to the Splatoon to bring back their beloved agent.

Warning!!! Octo Expansion Spoilers. Story: Kyle lost his memory. Cap'n Cuttlefish welcomed him to the New Squidbeak Splatoon. He is Agent 8 now. They must escape from the Deapsea Metro. But... Will it be possible? 80 levels. After that Romantic. And after that Returning of the Human Race? Maybe. Let's see how it will ends.

After going through the grueling missions in the Deepsea Metro, Agent 8 (Mike) finally makes it to the "Promised Land." He then finds himself facing discrimination for being an Octoling. Agent 8 finds by coincidence Agent 3 (Sarah), who provides him with a place to stay until he was able to get on his feet again. The duo slowly start to fall in love with each other, but stop themselves from doing so. After all, everyone will disapprove of their relationship.