According to MyAnimeList, season 2 will be titled Kantai Collection: KanColle Zoku-hen. However, the official title could change, but it’s rather unlikely.
While it’s a well-known fact, KanColle is based on a web-browser game from 2013. Thus, it’s not based on a manga or a light novel series, as most other anime. In turn, the story and characters are malleable, and the animation studio can be more free in choosing the direction. But that does not mean there’s no manga and light novel tied to the game, because there is! Check out more on the KanColle manga and light novels!
At this moment, there isn’t much information regarding season 2 of KanColle. But it’s confirmed that season 2 of KanColle will in-fact premiere in fall 2022.
The Confirmation of KanColle’s Release Came From @C2_STAFF on Twitter
Plot: In a world where humanity faces the threat of the abyssal fleet which has taken over the seas, special human girls who don weaponized outfits and possess the spirit of historical naval vessels known as kanmusu (艦娘, literally “fleet girls” or “ship girls”) are the only ones capable of countering them. The kanmusu live together at a naval base, where they spend their everyday lives as they begin training for battle.
The series features the destroyer Fubuki as the main character, with the storyline based on her point of view. Fubuki arrives at the naval base, where she meets other girls that she will eventually fight alongside. Despite lacking adequate combat training, she is recommended into the Third Torpedo Squadron by the admiral, and quickly finds herself sortied into battle. Upon being rescued by Akagi in a dangerous situation, Fubuki strives to do her best in order to train, with the hopes of eventually being able to fight alongside Akagi.
Source: C2_Staff Twitter Page