There are 18 different endings planned, one of them will be harem-style. We don't know yet which LIs will be included in it, because I am pretty sure it won't include all.
I write "harem-style", because some people have different ideas what "harem" means. To quote myself: "Will they end up in a literal harem, living together, happy to serve only the MC and forget their personalities, friends, and family? No. I think that is one of the most important things to keep in mind. They all have backstories, personalities, and their own life. That's one of the things I like about that game. The LIs are at eye-level with the MC. They are not just "collectibles", there to just fall for him and get him off, like in some harem games."