OOoooohhhhhohohoho This was very nicely foreshadowed, in my honest opinion!!!!!!!!!!!! (I always wondered about this couple, since it was show that Ibara was already kinda 'there' in that flashback from Rintarou's past!(Where Seimei's soul was eaten twice by his mother, lol) And he was a kid! A baby! And both Rintarou and Izuna(and Seimei too) were also show to have been together in school as kids/teenagers!) Wao! :0
Also, I for real thought the group separating would lead to one being hyped and the other being 'boring' but, oh man, isn't this a super pleasantly surprise! I'm SO happy of being wrong!!!!
(and man, that fiancé sir is so fine...)
Thank you for the amazing translation!!!!!!!!!!!!!!