Noun and する verb
はっしょう
デコポンは日本発祥のみかんの品種です。
Dekopon is a kind of mandarin orange that originated in Japan.
Your auspicious departure from another world is your origin story. You originally came from another place, and you had to leave there gloriously before you could enter this world.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.