There's no ceremony, no announcement, just Grimmjow showing up with a bag that had a bow in the same shade of blue as his eyes. he grunts. Written on the little attached card is 'Happy birthday, or whatever' in surprisingly neat cursive writing. Most would assume that the arrancar were all unable to read or write.
"I don't know what a birthday is but I heard today is yours. So, happy birthday or whatever." Inside the bag lay a few things that Ichigo probably wanted or needed. If asked, the arrancar would likely vehemently deny that he paid that close attention to his boyfriend. Ichigo
Ichigo looks up from his desk, taking note of the small gift that Grimmjow carried in his hand, and despite the usual scowl on his face, it shifts into a warm and loving smile. Standing from the seat and made his way over to him, accepting the gift.
"Thanks, Grimmjow." There was a faint but appreciative chuckle, and he moved towards him, a kiss planted on the arrancar's lips. "I'll explain birthdays to you, but for now, how about we spend time together, yeah? I think we've earned it."