Start
Beginning, Opening
noun, する verb
The open of the start is the start or beginning.
かいし
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
このゲームは、明日はいしん開始です。
This game will be released tomorrow.
先行予やく受付を開始しました。
We've started accepting preorders.
現在、トーフグは枕業界で巻き返しを図っており、新しいモデルの枕の販売を開始した。
Tofugu is currently still working to catch up in the pillow market, so they started selling new models.