"Wrong Way to Use Healing Magic" centers on Ken Usato, an ordinary high school student who is unexpectedly transported to a fantasy world alongside two of his classmates, Suzune Inukami and Kazuki Ryuusen. While Suzune and Kazuki are recognized as heroes with exceptional combat abilities, Ken is initially overlooked due to his lack of apparent talent. However, he is discovered to possess a rare aptitude for healing magic, a skill typically reserved for support roles in this world.

Ken is taken under the wing of Rose, a stern and highly skilled healer who trains him rigorously. Unlike traditional healers who remain on the sidelines, Rose teaches Ken to use healing magic in unconventional and aggressive ways, such as enhancing physical strength, endurance, and even using it offensively in combat. This unorthodox approach transforms Ken into a formidable fighter, blending support and combat roles in a way that defies the norms of the world.

As Ken grows stronger, he becomes an integral part of the kingdom's efforts to combat a looming threat from demonic forces. His unique abilities and determination earn him respect and recognition, even as he struggles with the immense pressure and responsibility placed upon him. The narrative explores themes of perseverance, self-discovery, and the redefinition of traditional roles, as Ken challenges the preconceived notions of what it means to be a healer.

The story balances action, humor, and character development, with Ken's journey serving as the focal point. His relationships with Suzune, Kazuki, and Rose evolve over time, adding depth to the narrative. The manga also delves into the broader political and magical dynamics of the fantasy world, providing a rich backdrop for Ken's growth and the challenges he faces. Through its engaging plot and well-developed characters, "Wrong Way to Use Healing Magic" offers a fresh take on the isekai genre, emphasizing creativity and adaptability in the face of adversity.