Objectives: This study aimed to clarify the effect of an intervention using a head-mounted display with a web camera set at a modified pitch angle on spatial awareness, sit-to-stand movement, and standing balance in patients with left and right hemisphere damage. Methods: The participants were 12 patients with right hemisphere damage and 12 patients with left hemisphere damage. The line bisection test, a sit-to-stand movement, and balance assessment were performed before and after the intervention. The intervention task involved pointing at targets 48 times in an upward bias condition. Results: Significant upward deviation on the line bisection test was noted in patients with right hemisphere damage. The load on the forefoot during the sit-to-stand movement was significantly increased. The range of anterior–posterior sway during forward movement in the balance assessment was reduced. Conclusions: An adaptation task performed in an upward bias condition may produce an immediate effect on upward localization, sit-to-stand movement, and balance performance in patients with right hemisphere stroke.