Responses
It wasn’t the one I was looking for but thank you for the recommendation! I’ve been planning on reading on & off for ages so thank you for reminding me!! (Incase your wondering I did find the manga I was looking for it was called eigyou nika https://www.mangago.me/read-manga/eigyou_nika/ )

Looking for a manga I read ages ago, office workers setting one had black hair the other was light brown/blonde. I can’t remember if they started off as rivals but I know the eventually got on really well and were secretly dating. They were both regarded as the good looking guys in their department. The black hairs guy was the more outgoing and chatty one & the seme .I remember their chibis being really cute and there was a sequel manga too.
Super vague but I’m trying my luck!