This is really great! Agyo i think is meant to be a gaurdian lion dog like the statues in front of temples.

Thank you for watching my panting.
In China,people always put stone lion statues in front of their houses of temples to keep the evil spirits and gosts away.Those statues are exactly lion.But when they across the sea from China to Japan,the Japanese call them"狛犬(こまいぬkoma-inu)".In the game,Ayou looks just like a dog.
In China,the stone lions appears in pares most of times,one male and one female.The male one with a ball and the female with a lion cub.But it's different in the game because Agyo is the male with the ball,and hi has a grandpa.If we consider Ayou as his grandpa's lion cub,then there are sonething in common.
About Ayou's species,I think he is just a symbol,a totem.He come frome Indian Buddhism,where the people exactly knows how lion looks like.When he come to ancient China,a place with no lions,ancient Chinese people can only imagine how lions looks like from tells and stories,that may explain why male and female stone lions both have mane.When he walks father formChina to Japan,the appearance and stories of Agyo has been changed alot.So that's why Agyo in Tokyo-after school-sumonners is a lion but looks like a dog.
And,there are different kinds of statues in front of building,they have different functions,such as kylin and 貔貅（I can't found it's English name,maybe it's beacuse it only appears in Chineae myths）.Kylin can bring luck,and 貔貅 can bring whealth.
I think those mythical creatures are really interesting!

Thank you for the background on those statues . That history and relationship between Agyo and his grandpa's roles was interesting. That all really makes me like him and wonderful art more.