Hmm well, this one the Seme is somewhat interested in the Uke, the uke takes care of the seme(loves him) and doesn't really disappear, just states he would leave :
http://www.mangago.me/read-manga/bikkuri_suru_hodo_doji_na_koi/mf/v01/c004/2/
Overdose
http://www.mangago.me/read-manga/yatteraneeze/
Aishuu
Destiny cross
Any manga where seme doesn't really cares about uke but the other takes care of him or is always around and seme realises that he loves uke only after uke disappears or finds someone other or simething like that.. and yeah i hope your suggested mangas are completed cause i just can't stand reading an ongoing ones >___<