Yaoi manga with school student who are rivals? It would be nice if it had some interesting...

http://www.mangago.zone/read-manga/junketsu_drop/

You might like this one!

Thank You (●'◡'●)ﾉ

Dammit! You beat me to this suggestion!

http://www.mangago.zone/read-manga/renai_kyoutei_nukegake_nashi/
http://www.mangago.zone/read-manga/yumemiru_otokonoko/mf/v01/c004/5/
http://www.mangago.zone/read-manga/versus_x_lovers/
http://www.mangago.zone/read-manga/koi_nante_shinai/
http://www.mangago.zone/read-manga/kirai_kiraimo/
http://www.mangago.zone/read-manga/dear_my_mister/mh/v01/c006/5/

http://www.mangago.zone/read-manga/junketsu_drop/

http://www.mangago.zone/read-manga/owaranai_fukou_ni_tsuite_no_hanashi/

http://www.mangago.zone/read-manga/koi_nante_shinai/ rivalry may be a bit one sided

http://www.mangago.zone/read-manga/sekai_wa_kimi_de_mawatteru/ at least one of the couples and all the stories are pretty cool

woops sorry if I doubled up on suggestions...started this last night, got distracted, fell asleep, and just submitted without checking to see if anyone else had suggested any...