Klein is a friend of Ace from the region of Dragoza. His primary motivation is his strong desire to become a Dragon Caller, just like his friend, though he is frequently ridiculed and doubted by others under the assumption that he cannot see the Drops. Possessing a friendly nature and keen observational skills, Klein chooses not to rely solely on the path of a typical Dragon Caller. Instead, he develops his abilities in technology, becoming highly adept at using a tablet device to observe, analyze, and relay critical information to his allies. In the story, Klein acts as a steadfast supporter and strategist within Ace’s group of companions, offering technical insights that aid their missions. His key relationship is with Ace, whose success he wishes to emulate. Klein’s character development is driven by his persistent journey to prove his worth and achieve his goal of becoming a Dragon Caller, facing the challenge of being underestimated by his peers. His most notable abilities are his technological proficiency and his sharp analytical mind.