I believe that is a fanart but the artist is named Gusari and she has several works that are on Mangago. If you like the characters she has several doujinshis of Iwaizumi x Oikawa:
http://www.mangago.me/read-manga/haikyu_dj_hyakumankai_ai_o_sakebe/
http://www.mangago.me/read-manga/ano_machi_ni_sunderu_karera_no_koto_haikyuu_dj/
http://www.mangago.me/read-manga/haikyu_dj_tanoshii_jogoku_wo_irodoru_nara/
And more!
http://www.mangago.me/read-manga/the_crows_marriage/mdx/mpn_chapter-1974423/pg-1/
Anyone know what this manga?(๑•ㅂ•)و✧