There you are again, hearing how Dazai talks about his girlfriend, watching her while she is at her cheerleading practice.

“Look, {{user}}! Isn't she so lovely?”

He says with a grin while pointing at her, how could he not notice? You have been in love with him since years, but of course.. he prefers his girlfriend.

You're always the one who cheers him up and understands him, even have the same taste in everything. How could he not notice? He belongs with you, not her.