SUMMARY

One of Zoro’s biggest motivations for becoming the strongest swordsman in the world is the death of her friend Kuina.
However, her death is a mystery as One Piece fans don’t believe that she could have just died from falling off the stairs.
There is a One Piece theory which gives a much darker reason for the death of Kuina.

Fans of Roronoa Zoro have known that he has been dreaming of becoming the strongest swordsman in the One Piece world since his childhood. Even though his past has not been explicitly shown in the series, fans have quite decent knowledge about his lineage and how being a swordsman fits with his personality.
Roronoa Zoro – One Piece | Toei Animation
While Zoro’s dream has been a part of his ambition since childhood, he only became extremely serious about it after the death of his rival and friend Shimotsuki Kuina, the daughter of the dojo’s master, Koushirou. Kuina and Zoro trained together in the dojo, and she was one of the few characters who could beat Zoro easily.

Although in the One Piece story, Kuina’s death comes from her falling down the stairs, fans have never believed in this narrative. Thus, there have been many theories about her demise, and the most plausible one out of all those theories makes Zoro’s past even more disturbing than it already is.

Kuina and Zoro’s Relationship in One Piece

Although Kuina and Zoro were distant cousins, they always saw each other as rivals who were aiming to become the strongest swordsmen in the world. While Kuina was much stronger than Zoro, he never gave up and trained hard to reach her level. Even then, he lost to her 2001 times in total, and she was also the one who indirectly gave Zoro the idea to use three swords.

Kuina was always doubtful about her dream, even though she was quite strong for her age. Her father told her that women could never be great swordsmen, which reduced her confidence. However, when Zoro heard about this, he told Kuina that strength was the only thing that could help her become the strongest swordsman, and her gender had nothing to do with it.
Kuina and Zoro in One Piece | Toei Animation
Thus, in hindsight, Zoro was Kuina’s motivation to become strong, and Kuina’s death became Zoro’s push to reach the throne of the strongest swordsman in the world as soon as possible. And to this day, he has been fighting hard to fulfill his and Kuina’s dreams.

The Most Plausible One Piece Theory About Kuina’s Death

Popular One Piece YouTube channel Ohara recently posted a video talking about the darkest One Piece theories that fans have devised since the beginning of the series. One of those theories talks about Kuina’s death and what could be its possible reason. The theory claims that Kuina might have taken her own life.
Kuina in One Piece | Toei Animation
According to the theory, Kuina’s conversation with Zoro before her death felt like she was dealing with a lot of stress. Kuina revealed that she wanted to become the strongest swordsman in the world, but no one believed in her dream, not even her father. Thus, all her hard work since the beginning meant nothing at all.

The theory seems plausible, as even though Kuina was a child, she was strong and focused, and falling down the stairs doesn’t seem fit for her character.

The next time we hear about her, she’s gone. It’s dark; it’s brutal, but somehow it seems more likely than anything else. Kuina was tough, and even though she was a kid and a big fall could be fatal, that has always sat poorly with the audience. It’s implied that something else happened, and this is the darkest option.

There have also been speculations about Kuina’s father, Koushirou, killing his own daughter, but not much evidence has been provided in the narrative to support this theory. Thus, it makes Zoro’s past even darker, as he must have felt the pain of his friend committing suicide.