i fully expected there to either be some plot twist about how he's not actually married to that woman anymore and it's just a formality thing bc they have a kid together, or, he realizes he doesn't rly have much of a relationship with her anymore and is just desperately clinging to what they used to be bc he doesn't wanna be lonely, only to move on with the new guy. the actual ending feels surprisingly bleak ┑( ̄Д  ̄)┍
looked it up on mangaupdates and there's actually side stories. six chapters, apparently