I searched Discord to list what Ocean said on the different girls so far: (main LI = romance + ending)
Bella: guaranteed main LI (Dom, Sub and normal routes
, could be different now that the game has taken a less dark route, won't be compatible with Amber)
Mila: guaranteed main LI
Nadia: guaranteed main LI
Nami: guaranteed main LI (Nami/Bella is possible but she is otherwise probably the least compatible with other girls, Nami/Mila
not possible)
Nia: guaranteed main LI, wasn't originally a planned LI
Sasha: guaranteed main LI and Ocean's #1 girl (as of August 2021), not planned to be part of any throuple
Sonya: guaranteed main LI and Ocean's #2 girl (former #1)
Victoria: guaranteed main LI (and can be compatible with every other girl (has the most throuples anyway))
Amber: main LI (two main routes, love or sub
, could be different now that the game has taken a less dark route)
Marla: main LI, should currently be married
Vanessa: main LI (sub and dom routes)
Zara: main LI, solo route only, threesomes possible but no throuple ending
Elsa: main LI but Ocean is not entirely sure yet, a lot about her can still change
Ayua: Ocean has not decided yet. Romance with her was mentioned a long time ago but at the moment she is not a LI. She's a special case.
Kate: Ocean refuses to say for now
Maja: formerly main LI, currently not planned anymore but under consideration
Robin: "lewdable," very low chance of becoming a main LI
Celina (Vic's therapist): not a LI
Cindy (teacher): should be lewdable but not a LI
Claire (Bella's aunt): we'll see how she develops but not a LI currently
Coach Hill: "bangable", "hook-up/lewdable" but no ending nor romantic relationship
Harrison (teacher): should be lewdable but not a LI
Karen: "lewdable" but not a LI
Layla: "lewdable" but will "never" be a main LI
Miriam (one of the twins): not a LI
Nancy: not a LI
Nicole (reporter): not a LI
Nojiko: currently not a LI "but nothing is ever set in stone"...
Nora (one of the twins): not a LI
Saki (Nicole's assistant): not a LI
Genevieve, etc: ??? (nothing mentioned) the main LI list is not necessarily over yet although Ocean has a limit, and we might be introduced to some more girls (like the women's first team for instance).
Note: As of October 16, 2021, Ocean has said that the list of LIs can be expanded to more LIs but it is also possible that some LIs will be dropped, except for the eight that are listed as
guaranteed.
Update February 2023: as of Chapter 4.5, "less than 5" new LIs are yet to be introduced.
Note2: There will be no harem route. One was originally planned (although it would not have included every girl) but the game took a lighter tone, of healing, than was first thought, and the harem route does not fit the story anymore. You should still be able to bang virtually every girl in a playthrough but having a romantic relationship with several girls being aware of each other is a whole different thing. There will be throuples for the compatible girls, but no more than that.
I have summarized this myself, if you want to hear from the source itself, most of the updated info regarding harem comes from here.
Update: only 3 throuples are planned as of summer 2022, there might eventually be more or fewer but that's to say that throuples will be rather the exception and in most cases won't happen.
