JiaMing (which is a clear Mandarin name) is either an 8 year old (not even giving the benefit of the doubt of being 9 or higher) or this is literally the first game he has ever played of this genre. I know plenty of chinese people who can at least distinguish Pokemon and Digimon, especially from Taiwan, Malaysia and Hong Kong. In fact, most of them who know Pokemon don't even know jack shit about Digimon since the former is far more popular and established than the former. I've been to several minor cities across Asia and every arcade has some pokemon in there, whereas Digimon is very niche in comparison.