As Ichigo gets older, the child-like attachment quickly becomes something more, and, as Aizen is also put under Shinji’s care, possessive. The first thing the two do once they properly meet is fight, with Ichigo being the aggressor and Aizen merely indulging him. It ends in a draw and the two come to some sort of agreement, quickly bonding and, much to their caretaker’s chagrin, teaming up to bully the blonde, whether it be carrying him around by the back of his shirt, making suggestive comments in his ear, or simply laying on him so he couldn’t leave the enclosure.
Grimmjow’s integration into the pack wasn’t nearly as smooth. Between his thirst for battle and his need to be alpha, his fights with the two were far less friendly and far more violent. It eventually got to the point that many just figured it wasn’t worth it and to just introduce him to a more submissive carrier. Then Ichigo snapped, tearing off his arm and pinning him to the ground, forcing him to submit. Luckily they’d been able to reattach the limb but the hybrid’s pride was a whole nother story. After being overwhelmed so easily he’d slink shamefully around the edge of their shared enclosure, sulking and hissing at anyone who came near. It took about a month for him to actually warm up to his new packmates and another two weeks before Shinji could actually approach him.