The Japanese word for coffee is
コーヒー

kohii

Japanese Definition

コーヒー
1. n. Coffee sign in kanji
2. n. coffee
3. n. Usage: The spelling of コーヒー is much more common generally, but 珈琲 is found relatively frequently on signs for restaurants and on some menus.

珈琲
1. (ja-see, コーヒー)

コーヒー豆
1. n. coffee beans The seed of a tropical plant of the genus Coffea. Prepared by drying, roasting and grinding for making the beverage coffee.

Dictionary entries from Wiktionary