Kyoya Ida

Kyoya Ida is the protagonist of the Seinen Detective manga 'Jiraishin' also known as 'Ice Blade'

Background
Not much is know of Ida's earlier life all that is known is his father was a police officer (whom it was implied Ida had a close relationship with) who accidentally shot dead a civillian and then unable to handle the guilt took his own life his boss throughout half the manga Narita was his father's partner.

Ida at some point joined the Japanese Police eventually and became a detective he is known as one of the best detectives even though his methods not universally popular with some of his superiors and colleagues but Nartia and his partners trust Ida absolutely.

Ida is known to frequently use lethal force to solve cases and he is often assigned cases that affected the city

Personality
Kyoya is shown to act cold and emotionless to most people and for him the ends justify the means but is also shown to have a biting and sarcastic wit.

Ida is shown a more human side particuarly with the very few people he calls friends and does care about them more then he at times lets on most notably Tsuyoshi 'Hachimaki' Yamaki (his first partner in the series), Hachimaki's wife Yukari and her son but also Narita (his boss and his fathers old partner) and his second partner Eriko Aizawa.