Yes it's a scam because they just grab some picture of a Japanese nationality and used it to include to their team. And with that move it's clear that they are shady, no matter how legit they are because they'll defend themselves for those pictures that are scattered through social media still they don't have any willingness to show their team or themselves. They have shady priorities on this project, don't invest.
P.S: This belongs to alt coin discussion.
My group friend say Ethconnect is from vietnam :/ but I don't know it's true or not.
No one knows on where are the developers of ethconnect came from. Does your friend do have enough resource and proof if the whole ethconnect team came from Vietnam? You shouldn't make any claims if there is no appropriate proof for it. But what matters most now is just keep on avoiding this scam so that you'll be safe.