The ending point of the Tomo-chan anime in the manga can be a bit tricky to determine. Sometimes, the anime might condense or expand certain storylines compared to the manga. You might need to do a detailed comparison to figure it out precisely.
I don't know for sure who Tomo is in this context. It could be the name of a person who is the translator or the founder of the translation project related to these novels.
I think there might not be a direct connection. 'Meme girl chan' could just be a random internet character, while manga is a form of comics. They could potentially intersect in some online creative works, but it's not a given.