Chrome is a young man of average height and build, characterized by his spiky brown hair and round brown eyes. He typically wears a dark blue short-sleeved shirt with matching pants, secured with a rope belt, and carries two cross-body satchels for holding collected materials. A rope tied around his head serves as a headband. As a resident of Ishigami Village, Chrome is a descendant of the astronauts who were in space when the petrification event occurred 3700 years prior to the main story. His name is a reference to the chemical element chromium.

Chrome possesses an exceptionally energetic, passionate, and curious personality, demonstrating a genuine and deep love for science, which he initially understood as sorcery. He has a habit of exclaiming "baaaad" to express that he finds something cool or amazing. He is confident in his intellect, enough to challenge Senku despite being outmatched. Chrome is selfless and exceedingly brave, displaying unwavering loyalty to his friends. He famously resisted threats and torture from Tsukasa, refusing to reveal information about the village or Senku's inventions. Although he can be a loudmouth, he knows when to remain silent. While brave, he is also naturally combative and quick to challenge anyone who encroaches on his self-proclaimed roles. In matters of romance, Chrome is notably naive and oblivious, particularly regarding his own feelings for his childhood friend, Ruri.

Initially fascinated by nature's resources and minerals from a young age, Chrome's primary motivation is his insatiable curiosity about the world. He has spent years experimenting with different materials through trial and error, driven by a desire to understand how things work. A significant part of his early motivation was to find a cure for Ruri's illness, which led him to collect numerous herbs and minerals for his experiments. After meeting Senku and learning about the vast scientific achievements of the modern world, his motivation expands to include rebuilding that knowledge and exploring new frontiers alongside his new friend.

In the story, Chrome serves as one of the main protagonists of the Kingdom of Science. Initially introduced as a rival "sorcerer" from Ishigami Village, he quickly becomes Senku's closest ally, most trusted confidant, and unofficial right hand. He is one of the Five Wise Commanders and holds the distinction of being the only member of this group who is a post-petrification human. Chrome's role often involves utilizing his expertise in exploration to gather essential raw materials. He frequently works alongside the elder craftsman Kaseki, providing the creative ideas and designs that Kaseki then brings to life through his masterful crafting skills. As the series progresses, particularly in the events of Science Future, Chrome steps into a leadership role when Senku is incapacitated, taking charge of scientific experiments and development to prepare a counterattack against antagonists like Xeno.

Key relationships define much of Chrome's character. His bond with Senku Ishigami is central, as they become close friends due to their mutual love of science. Senku teaches Chrome the principles of modern science, while Chrome's practical knowledge and unique "flash of insight" ideas often surprise and assist Senku. He shares a loving but unspoken romantic connection with Ruri, the village priestess, though he is largely unaware of the depth of his own feelings. He is close friends with Ruri's sister, Kohaku, despite frequently calling her a "gorilla" and being beaten by her as a result. He collaborates extensively with Kaseki, the village craftsman, forming an effective idea-and-execution partnership. He also has a competitive but respectful dynamic with modern experts who join the team, such as the explorer Chelsea, viewing them as rivals to his self-proclaimed expertise in exploration.

Chrome demonstrates notable abilities that make him invaluable. His intelligence is highly gifted, particularly in the fields of natural science, exploration, and practical invention. Although he lacks modern education, his relentless curiosity and analytical prowess allow him to recreate complex modern items like a water wheel, a metal detector, and a drill using only his imagination. This earns him genuine praise from modern-era geniuses like Senku and Xeno. His specific expertise lies in exploration, with an excellent ability to locate rocks, minerals, and herbs, as well as a deep knowledge of geography and cave systems. While physically average compared to the village's strongest warriors, he possesses enough fitness to run long distances and perform pole vaulting to gather resources or navigate obstacles. He also showed a practical, if unorthodox, skill by training to reliably hit a specific "weak spot" with a spear.

Throughout the series, Chrome undergoes significant character development. Starting as a self-proclaimed sorcerer comfortable in his position as the village's sole genius, he experiences humility and amazement upon meeting Senku and learning about the true scope of science. He grows from a rival into a devoted student and then into an equal partner and leader. A key moment in his development occurs in the Science Future storyline when Senku is critically injured; Chrome steps up to fill the role of lead scientist, proving that Senku's teaching has enabled him to think and plan scientifically on his own. He learns not to be disheartened when his original inventions already exist, understanding that his accomplishments are still impressive for someone reinventing concepts from scratch. By the later stages of the story, even modern pre-petrification humans acknowledge that Chrome has become far superior to them in science and intellect.