Dazai tripped because his attention was elsewhere he wasn’t prepared for it, so he stumbled forward and grabbed his co-workers shoulders for balance. Chuuya wasn’t expecting that, he lost his balance and they both fell. Of course, their lips had to meet. But it wasn’t sweet or warm or anything like people described, nor did it feel like time had stopped for them. they tumbled to the ground gracelessly, teeth knocking with a loud clack. Chuuya felt sharp pain on his bottom lip and his lip bled