苦心 Kanji
苦心のかいがあった。 That was well worth the trouble.
苦心惨憺 Kanji
苦心惨憺の末、考え出した企画が、会議で一瞬にして却下されちゃうんだからな。 After all the trouble we went to in coming up with that project, it only took them a second to shoot it down in the meeting.
苦心談 Kanji
苦心買 Kanji
Japanese Dictionary
