I'm wondering if the Final_fantasy_XI tag is appropriate, considering that armor is as far i remember identical to the samurai artifact armor in said game...

Reminds me strongly of FFXI's Myochin armor set, used for Samurai's Artifact Armor. See here:
http://wiki.ffxiclopedia.org/wiki/Myochin_Armor_Set

I'm woefully unfamiliar with the actual style of armor though, and already half asleep, so I am uncertain if they are connected. Touhou has shown a connection to FFXI in the past however (Buront.)

That's totally the Myochin set.

Myonchin set.