hyp3r1 the game does not. The main ending is from deleting monika at the end. There is a few others (i have not played this in legit 3 years but I will try my best to remember). I know there was a slightly different ending if you made a poem for every girl. This means like every time you had to make a poem you made a poem for one girl, went back, did the same for another, then for the 3rd girl every time you had to do a poem. It gives you slightly different texts and messages and nothing too seriously new but still new nonetheless. Another ending I think is if you delete Monika before you even boot the game up or something like that. I know it does something but I cant remember if you deleted her before or after you booted the game up.... theyre not really endings so much so as easter eggs but yeah. The only real ending is from just playing the whole thing then deleting monika at the end.
most commonly referred to as the "happy ending", is where you save at the first poem game, and write a poem just for one girl throughout the week. you do this for every girl (sayori, natsuki, yuri, haha fuck you monika). the main goal is to see every characters special scenes (such as natsukis baking scene or yuris rag cheek escapade). both endings are canon to the game.
deleting monika or sayoris .chr file before you boot the game up will end at the "now everybody can be happy" scene with sayori hanging. not so much an ending, just an easter egg.
writing all the poems for each girl does result in different poems from each later on, but i cant remember what those poems are.