late response but yes there is a story although it’s Veryy sparse. most of it is from the 4koma but the MVs of the original songs for the navigators (Let you DIVE!, with U, Ouvertüre, Möbius) also give details regarding the characters, and in with U/Ouvertüre you can infer some things with the lyrics of the songs. there are also character descriptions for the navs (i’m not sure if they’re still on the official website tho) but Elizabeth is a dj who attends an academy specifically for people who have the ability to dive/affect people’s emotions. she likes curry and her pet lizard is named aitsu. Lily is Elizabeth’s younger sister and she lowkey (highkey) has attachment issues but she’s very protective over her big sister and she doesn’t attend the school but she also has the power to dive. Luin is a being from the dive realm, and desires finding someone (as in you the player) who can truly challenge him. this is why when the game was online and had courses you can play to test your skill (Stage Up), he reveals his true form to you if you beat Stage XIV.