Play Attack On Ueda Castle. To obtain the Chained Dragon (Inga Yomitsu), you must play in Hard or Chaos mode. Take out Kotarou Fuuma and all of his clones (three), then defeat Yukimura Sanada before beating Masayuki Sanada. Stop the water attack to make things easier for you on your way to Kotarou Fuuma and his three clones. Watch out for super-hyper Yukimura Sanada though. After finally defeating Masayuki Sanada, you will get a precious item report in the back of the castle on the first floor, on the right side, behind where one of Fuuma's duplicates were found.