Azuma Tanaka

Azuma Tanaka is Manabu Tanaka's grandfather. He always has an air of maturity and coolness surrounding him. Age doesn't stop him from impressing girls (or anybody for that matter) with his charms. He can also be a badass and beat people up if he wishes. Manabu is embarrassed by his coarseness and skirt-chasing but secretly worships the guy. He's actually so cool, both his grandchildren are acting out of character when he's present. Manabu's grandfather literally puts him to shame - he has such a complex about his granddad being so much cooler than him that it's far and away the leading cause of any not-so-stoic moments he has. He walked away from his role as family head and company president in order to raise Manabu. Doesn't seem to regret it one bit.