Employee benefit plans (Tables)

6 Months Ended

Sep. 30, 2023

Employee Benefit Plans [Abstract]

Net periodic benefit cost for defined benefit plans

	Millions of yen
	Six months ended September 30
	2022			2023
Service cost	¥	3,199		¥	3,014
Interest cost		1,216			1,742
Expected return on plan assets		(2,984	)		(2,829	)
Amortization of net actuarial losses		1,909			1,403
Amortization of prior service cost		(803	)		(802	)
Net periodic benefit cost	¥	2,537		¥	2,528
	Millions of yen
	Three months ended September 30
	2022			2023
Service cost	¥	1,600		¥	1,507
Interest cost		608			871
Expected return on plan assets		(1,492	)		(1,414	)
Amortization of net actuarial losses		954			701
Amortization of prior service cost		(401	)		(401	)
Net periodic benefit cost	¥	1,269		¥	1,264