Naomi is Akira's daughter-in-law because she is married to Akira's son Kenji. Kaito is Akira's nephew because Kaito is the son of Akira's brother Takeshi. Hina is Akira's granddaughter as she is Kenji's daughter, and Kenji is Akira's son.

Sora is related to Mei as first cousins. Sora is the child of Akira, and Mei is the child of Akira's brother Takeshi, making Sora and Mei the children of siblings.
Akira is married to Hiroshi, and they have three children: Kenji, Yumi, and Sora. Kenji is married to Naomi, and they have a daughter named Hina. Akira has a brother named Takeshi, who has a son named Kaito and a daughter named Mei. How are Naomi, Kaito, and Hina related to Akira, and how is Sora related to Mei? Provide a very short response.