Kozuki graduated from the 53rd course at the Army Military Academy.

In April 1938 Kozuki served in the 10th Independent Flying Chutai in China. The unit was at this time equipped with Kawasaki Ki-10s (Type 95).

Captain Takatsuki led five Ki-10s of the 10th I F Chutai from Jiujiang on 30 April and intercepted three SBs over Bangbu. Sergeant Shuzo Kogawa claimed one and killed one of two crew members who took to their parachutes. Sergeant Major Katsura Kichise claimed a second while the third was claimed as a shared by Yutaka Kozuki and Warrant Officer Seitaro Awao.

He took part in the attack on Hong Kong in December 1941.

Between July 1943 and June 1944 he served as leader of the 1st chutai of the 248th Sentai.

From June until August 1944 he served as leader of the third chutai of the 13th Sentai.

Captain Kozuki was killed on 4 August 1944 over Ambon.

At the time of his death Kozuki was credited with one shared biplane victory.

Claims:

Kill no.	Date	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1938
	30/04/38	½	SB	Shared destroyed	Ki-10		Bangbu area	10th I. F. Chutai

Biplane victories: 1 shared destroyed.
TOTAL: 1 shared destroyed.

Sources:
Japanese Army Air Force fighter units and their aces 1931-1945 - Ikuhiko Hata, Yasuho Izawa and Christopher Shores, 2002 Grub Street, London, ISBN 1-902304-89-6