Net pension cost of the plans for the nine months ended December 31, 2010 and 2011 consists of the following:

		Three months ended			Three months ended
	Millions of yen
	Nine months ended December 31, 2010			Nine months ended December 31, 2011
Service cost	¥	2,330		¥	2,283
Interest cost		1,026			1,011
Expected return on plan assets		(1,525	)		(1,514	)
Amortization of transition obligation		(3	)		42
Amortization of net actuarial loss		782			913
Amortization of prior service credit		(894	)		(895	)

Net periodic pension cost	¥	1,716		¥	1,840

Net pension cost of the plans for the three months ended December 31, 2010 and 2011 consists of the following:

		Three months ended			Three months ended
	Millions of yen
	Three months ended December 31, 2010			Three months ended December 31, 2011
Service cost	¥	776		¥	761
Interest cost		340			336
Expected return on plan assets		(506	)		(504	)
Amortization of transition obligation		(1	)		14
Amortization of net actuarial loss		260			304
Amortization of prior service credit		(298	)		(299	)

Net periodic pension cost	¥	571		¥	612