I've always thought MK and Mai are like brothers And it would be strange for them to think of each other in a romantic way Just imagine May felt ashamed of MK because he touched her or got close to her, buddy they were together 24 hours every day they see themselves as brothers
One of the best sibling duos since Spranne (Sprig and Anne from Amphibia) and Cuphead and Mugman (from the Cuphead Show of course) and Wander and Sylvia from WoY
Romance does not have to be involved in all relationships between characters Everyone likes MK and Mai's relationship to be a friendship without any romance involved I also think that MK is not interested in romance and I think he is too young to think about these things
I know people mostly like the Mei and Red son ships but I prefer Mei with MK they just have great chemistry together and who's not to say one of them falls for each other for season 5 or future seasons you know the classic they don't realize they have feelings for each other yet until something happens to trigger it