The good news is he's played in Urawa Red Diamonds' last 3 games, including a start. The bad news is he represented Japan's U-23s in between the 1st & 2nd games of that run: http://www.transfermarkt.co.uk/en/mizuki-hamada/leistungsdaten/spieler_118012.html
Thus far this season, he has 159 minutes over 11 starts in the J League, 512 minutes over 6 matches in the League Cup, and 1 half in the Emperor's Cup: http://www.transfermarkt.co.uk/en/mizuki-hamada/leistungsdaten/spieler_118012.html
Is Mizuki still eligible for the USA? We are in need of centerbacks. He last started on July 10 for Alibrex Nigata. He's 23 years old, 6 feet tall. http://us.soccerway.com/matches/2013/07/10/japan/j1-league/jubilo-iwata/albirex-niigata/1444959/
I wonder what his background is? Kind of mysterious. I'm sure people will come in here barking about "MLS PLAYERS DESERVE A LOOK", "THIS IS RIDICULOUS", "HE HASN'T EVEN DONE ANYTHING" etc. but if Hamada eventually starts getting a good run of starts in the J-League I'd like to see him get at least some attention. The J-League is a pretty cool but obscure league and I feel like even if he excels there, he's likely to get overlooked.
As I recall from the discussion around Gotoku Sakai, potentially US-eligible Japanese nationals are extremely hard to pry away if they're located in Japan because Japan doesn't recognize dual citizenship. So Hamada would have to renounce the citizenship of the country he calls home in order to play for the US. That said, the J league is a good league, likely a higher level than MLS (where Besler, Gonzalez, & Goodson play), and if he begins to start regularly and play well, it couldn't hurt to invite him to a camp. But there's a lot of ifs in there & I don't expect him to ever play for us.
Hamada is set to return to Urawa Reds after a season-long loan at Albirex Niigata. He had a tough season, making only 6 league appearances for 330 minutes total. http://www.albirex.co.jp/news/top_team/40777 To answer an earlier point about his NT eligibility (which is currently a moot point, obviously), he'd need a one-time switch to play for the US. He played in 2012 Olympic qualifiers for Japan.
Hamada scored the winning goal in the Reds' 4-3 win over Tokushima Vortis in a J.League Cup group stage match. Goal @ ~2:10
Hey another Japanese-American. The biggest problem is they're not going to renounce their Japanese citizenship. J-League is cool though, except for the goalkeeping.
Hamada came on for an injured teammate at half-time, helping the Reds win 1-0. They shut out one of the most formidable offenses in the J-League.