The most common and most likely answer to this crossword clue is the 5 letter word KYOTO
K
Y
O
T
O
More clues leading to the result KYOTO
- Regeneration of Tokyo, Japanese city
- Old Japanese capital Tokyo replaced
- Eastern city right about fiddle backfiring
- Play around in floor in Japan
- 1,000 yen over? Time for old Japanese city!
- Japanese city suitable to host play from the east
- Eastern city right to screen play that’s uplifting
- Exotic Tokyo, Japanese city
- Enemy finally took out former capital
- First couple in Tokyo travelling eastwards, finding old capital
Buddy explains!

The straight part
We know that "Old Japanese capital" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case old japanese capital = kyoto.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.