Sorry, that is taken for Nihona! You can claim any of the other islands, though!
BTW: Please consider who your european mirror had major rivalries or alliances with when making claims. For example: Uniroyaume should probably be placed next to Deutlind and Ritainings, which had major operations for and against each other during WWI. I will not force interactions, but remember: situations are very similar. If you need help, look up WWI and substitute the names.