From Bulbapedia, the community-driven Pokémon encyclopedia.
Kaisei (Japanese: カイセー Kaisē) is a character in Pokémon Diamond and Pearl Adventure!, a friend of Professor Rowan and the father of Hareta. He first appeared at the Sinnoh League Tournament to watch his son compete.
For an unknown reason, Kaisei knows where the Pokémon Giratina lives, and knows it personally. When his son Hareta was born, Kaisei gave him to Prof. Rowan so he could continue his journey. Much later, he came to the Pokémon League to watch his son compete. When Hareta was being beaten by his opponent Koya, Kaisei gave him a pep talk that made Hareta turn things around. However, the battle was interrupted by Neo Team Galactic. After they were defeated, Agent Hansom of the International Police attempted to arrest Kaisei, believing that he was planning to use Giratina for evil purposes.
This listing is of Kaisei's known Pokémon:
|| カイセー Kaisē
|| From 快晴 kaisē, "good weather". Related to his son's name as 晴, which has a on-yomi reading of sē, has a kun-yomi reading of hare.
|| Same as Japanese name.
| Chinese (Taiwan)
|| 凱晴 Kǎiqíng
|| From the name 凱晴 kaisē. Shares the character 晴 with his son's name (小晴).