Neptune is the one who is in least contact with the group. He mostly just does his own thing, wich is often fishing, taking care of fish or studying fish topics. He is a quiet guy who doesn't speak much unless it's necessary or if he has a funny thing to say. He and his brother can seem like opposites but they get along very well. The one Neptune is closest to is Jupiter, who also likes quieter outings and activities, like a game of monopoly or cards. Neptune is always direct and expects people to be direct and honest with him too, even if it can sound rude sometimes.

His voice is mostly emotionless and soft.