蹴込み is read as けこみ (kekomi) and means riser.
けこみ
kekomi
けこむ
to kick in(to)
ける
to kick
もうしこみ
application
ふりこみ
discarding a tile that becomes another player's winning tile
ひとごみ
crowd of people
みこみ
side of a structural member
つっこみ
straight man (of a comedy duo)
おりこみ
insert (in a magazine, newspaper, etc.)
いきごみ
ardor
なぐりこみ
raid
うりこみ
sales promotion
もちこみ
bring-your-own (e.g. food and drink)