Maaaan, I really like Seo's sincerity. Usually the otaku MC is written as kind-hearted, like ... a little bit strange, but sometimes doing random good deeds or being specially kind in the past. However, Seo is always attentive to his surroundings, and being upfront with what he feels. So "randomly kind" is not the only positive trait that he has.
The growth of his character from a pessimistic about himself, especially in the festival arc, to this person who has made peace with himself is really captivating. The little mouse he was to the wholesome doggo he is now captured his journey perfectly. The girls' feelings might be become a source of "conflict" to what he wants. Especially because he is a sincere person, so taking one choice might be difficult for him, but ... HAREM END! SEO! HAREM END! WE APPROVE!!