Start with the vibe, not the era
The Japanese pages ask for an era first. This page asks for a feeling. The vibes are elegant, gentle, serene, heroic, sweet, cold, regal, mysterious, playful and fierce. Each name carries a few of these tags. Fuyuka 冬花 (winter flower) and Tōya 冬夜 (winter night) are cold. Hayato 隼人 (falcon person) is heroic and fierce. Kaguya 輝夜 (shine plus night) is regal and mysterious. The tags are a rough guide, since a plain name like Matsu 松 (pine) is tagged cold too.
Japanese style or fantasy-world style
Japanese style joins a family name and a given name that share your vibe, and shows the kanji meaning. Fantasy-world style draws from the invented-kingdom pool, for a hero who wakes up in another world: a given name such as Gabrielle with a house name such as de Castellane, a castle town in southeast France. A name-order switch puts the family name first or last. Japanese order is family first.
Pitfalls
A few names are famous as characters, so search before you give one to a new hero. Look at Check meaning tags, such as Sena, which sounds like an English word for a herbal laxative. If you know the era you want, go to the Japanese name generator. For long lists, see girl names and boy names. How glosses are checked is in editorial standards.