Solution
1.N1a+ 2.Kx1a 3.L*1c 4.K2a 5.L1b+
1.N1a+ 2.Kx1a 3.L*1c 4.K2a 5.L1b+
1.N*2e 2.K1b 3.N*2d 4.Px2d 5.N1c+ 6.Kx1c 7.+B3a 8.K2c 9.+B2b
1.P*5b
if 2.Rx5b, 3.R2a+. if 2.Gx5b, 3.Bx5e
1.P*2d
there’s no way to prevent P2c+ for White.
1.R*3a 2.Kx3a 3.G*4b
1.G*2b 2.Kx2b 3.B*3a 4.K1b 5.+R4b
1.P*5b
if 2.Rx5b, 3.P*5c 4.R5a 5.Rx5d
1.P*8c
if 2.Sx8c, 3.Rx6a+. if 2.Kx8c, 3.B*5f
1.R*1d 2.K2c 3.G*1c
1.S*1c 2.Kx1c 3.G1d 4.Gx1d 5.+R2b