From Tsukuba Station, walk south to Tsuchiura Gakuen Sen (towards the very tall Mitsui Building and away from the parking lots).
When you get to Tsuchiura Gakuen Sen, turn right and walk one block. When you get to the corner where Jusco is right behind you, go south.
Keep following this road south past Dayz Town (on your left), Okura Frontier Hotel Epochal (on your left), Tsukuba International Congress Center (on your left), Ishimaru Denki (electronics shops, on your right), Tsutaya (on your right), the AU Shop/Mini Dealer (on your right) and Tsukuba Center for Institutes/JISTEC (on your left).
Just after Tsutaya and the AU shop, you will see Minami Odori. Cross the intersection and walk past Kojima Denki (electronics shop, on your right).
There is a road in between the Kojima Denki store and the parking lot. Turn right onto that road and follow it past the Seria 100 Yen Shop until the road ends in a T-junction.
Turn left. Ninomiya House starts on the corner of the next intersection. It is a huge, square, brown building with a unique shape.