Help with Japanese Medal

[1917-1919]

I have been hunting to find out what this is, any ideas?IMG_0151 (640x480).jpg

IMG_0152 (640x480).jpg

[J7W22007]

It's a badge for diligence or good attendance　award. Non-military??

Translation:

Front
精勤賞 (Sei Kin Shou) - Diligence award.

Top star
青　（Sei） - Youth

Back (Left)
東京市立高等青年學校　
（Tokyo Shi Ritsu Kou Tou Sei　Nen Gakkou) - Tokyo City Advanced Youth School

Back (Right)
研究科　（Kenkyu Ka) - Research Department.

Best regards,
Taka