Pretty sure it's this series. http://www.mangago.me/read-manga/k_sensei_no_yajuu_na_aijou/
it's this one http://www.mangago.me/read-manga/ameiro_paradox/
it's K-SENSEI (￣∇￣")
Ups...sorry, I didn't see those 4th page>.< Those are http://www.mangago.me/read-manga/k_sensei_no_yajuu_na_aijou/ or K-sensei's series by Natsumizu Ritsu.
thank u everyone!!!!
http://www.mangago.me/read-manga/doushiyoumo_nai_keredo/mf/v02/c009.6/1/ anyone know the name of the manga on the fourth page.....??