Chinese

		sincere desire; wholeheartedness	sincerity
trad. (誠心誠意)		誠心	誠意
simp. (诚心诚意)		诚心	诚意

Adverb

誠心誠意

1. earnestly and sincerely

Japanese

Pronunciation

• On'yomi
• (Tokyo) せいしんせ​いい [sèéshíńséꜜèì] (Nakadaka - [5])^[1]
• IPA^(key): [se̞ːɕĩnse̞ːi]

Adverb

誠心誠意 ‎(hiragana せいしんせいい, romaji seishinseii)

1. in all sincerity; with one's whole heart

References

1. ↑ 1998, NHK日本語発音アクセント辞典 (NHK Japanese Pronunciation Accent Dictionary) (in Japanese), Tōkyō: NHK, ISBN 978-4-14-011112-3