Honestly I never saw Guri and Shikimi as potential harem members. Shikimi has had some development and focus sometimes but not enough and Guri feels she is more suitable for the role of Female BFF and comedic relief.
@TetraSky I think there is only one chapter left and the epilogue.
One thing I don't like about those boys is that you don't just take someone else and leave the other person alone regardless of what they feel about each other if they already have a previous commitment.