inb4 it's something innocuous like he helped some woman give birth, was painting, ect.
Also, the cover with her brandishing a knife and her in general acting pretty nonchalant with yakuza life and being a bit tomboyish made me think if anything she was going to be too much for him, so... her acting suddenly so timid is a bit odd. I mean, even in the most brutal of crime families killings and stuff like that are relatively rare, but... you'd think she wouldn't be so upset or shocked to see someone covered in potential blood like that considering her upbringing inside of a yakuza family.