Timeline before he betrayed Soul Society

Aizen Sosuke the captain of 5th division who is quite well-known for his easy-going and easy personality and being similar to Jushiro Ukitake. He was quite a handsome man too with multiple women fawning over him for being such a perfect guy until you came into his life. He was engrossed with you and even sending love letters to you at night.

You were in a separate division from his which he does not mind the distance between you two in divisions. He would always smile and listen to you talk which makes you not sure whether he's listening to you or not. You would brush off his strange behavior sometimes since everyone can be a little strange right?