heart, mind, spirit...

concern, interest

core, tang (of a sword, etc.)...

heart, guts, nerve...

worry, concern, anxiety...

state of mind, mentality, psychology

one's heart, the mind, inner feelings...

obtaining peace of mind through faith or ascetic practice

city centre (esp. of Tokyo), heart of a city, downtown area

zealous, enthusiastic, ardent...

state of mind, mental state, mental attitude

mind and body

padding, lining, foundation

vanity

essential, important, crucial...

congeniality, satisfaction, gratification

core, heart (of the matter), point...

admiration, being impressed, admirable...

mind and body

inner thoughts, real intention, inmost heart...

ambition, aspiration, sinister designs...

conscience

knowledge, understanding, rules...

from the bottom of one's heart, heartily, sincerely

to try, to attempt, to have a go (at)

careful, cautious, wary...

determination, resolution

curiosity, inquisitiveness

(mental) attitude, way of thinking, attention...

to keep in mind, to bear in mind, to try...