波多野せい = Sei Hatano
Lucky, she recently played for Yuriko Kuronuma's sayonara concert in Yokohama and her name is on the advertisement sheet:
http://www.artsisland.com/kuronuma/150221_1_800.jpg
Changed her name for all Arslān releases.
鶴来正基 (and not
鹤来正基, typo from submitter).
Check booklet, page 12, low right corner.