Hi Kubur,
Marcus Sesko's Swordsmiths of Japan lists three makers signing in this way so it may be one of them:
MORITSUNE (盛常), Eishō (永正, 1504-1521), Kaga – “Moritsune” (盛常) MORITSUNE (盛常), Kyōroku (享禄, 1528-1532), Bungo – “Moritsune” (盛常), “Hōshū-jū Takada Moritsune saku” (豊州住高田盛常作), “Moritsune saku” (盛常作), Taira-Takada school MORITSUNE (盛常), Eiroku (永禄, 1558-1570), Bungo – “Hōshū Takada-jū Taira Moritsune” (豊州高田住平盛常), “Taira Moritsune” (平盛常), Taira-Takada school, itame mixed with masame and shirake, gunome-midare in ko-nie-deki with a compact nioiguchi.
That said, my initial feeling was that the blade was later than this but if you want to post some better pictures of the blade itself including any activity in the edge and tip then you might get some better views than mine.
Best,
John