I loved this film. Based on either novels or manga (I'm not sure which) which have been popular for some time in Japan, it's directed with a feminine sensibility by Ms Shimako Sato who also wrote the screenplay. What this means in that there's a lightness of touch, a hero who is compassionate (he helps feed locals orphans living rough) fallible good-humoured and masculine without being macho, there's an element of humour and understated romance. There is also plenty of action. When Endo is broken out of prison by local thieves, he is given a book on how to become a master thief. The various elements play to both his intelligence and skills and involve a lot of parkour (the French sport of leaping around buildings) and provides everything he needs to challenge K-20.
The other main players, apart from the masked K-20 and Endo, are Baron Kogoro Takechi the senior police officer in charge of the K-20 and his fiancee Duchess Yoko Hashiba who seems to have reservations about her impending marriage. When Endo rescues Yoko from the clutches of K-20, he takes her to his world, a place of deprivation that Yoko never knew existed and which immediately sparks her social conscience. So we have a three-hander, plus master villain K-20 always waiting in the wings to strike.