She is a fair-skinned girl with short purple hair and golden eyes. The clothes she has worn in the series are limited to her school uniform which is composed of a black coat, white shirt inside, pale pink tie, light gray skirt, black stockings and white shoes. Her emblem when using her stick is the sun.
When using her stick, her hair gets lighter at ends of it, like highlights.
She was at first an outgoing and quite optimistic girl, seeing how she would always soend time with her family and friends happily. After her father murdered three boys to avenge her younger sister, Airi Komura, her life changed drastically. Her classmates began to bully and taunt her about her father being a murderer. After she finds that her mother is extremely sick and has fallen into a coma with a very low chance of recovery, she entered a state of depression and loneliness. For that, she as contacted by the Mahou Shoujo Site, and was given her Compact Mirror stick and a Slaughter Note.
She is quite pessimistic and straightforward, due to the events that have happened in her life in such a short time. She does not fight back when Melissa Maina Mitsushiro bullies and taunts her constantly, though she admitted to Takuma that she wants to kill her but doesn't want to be like her father. As the story progresses, it was shown that she starts to smile more often after her friendship with Sakura Sakaki. She is also worried easily as Sakura risked of going to Kichiro's basement, which Kayo said that that was reckless.
She can copy other stick powers via compact when she interacts with any magical girl. Although it has a limitation of only having space for 10 copies of sticks. Currently, she has completed the 10 spaces available to copy sticks. However, she can only use their abilities once. When she uses her stick, her hair changes color and blood flows from her mouth.
Below is a detailed list with all the information known so far of the sticks copied:
|Sakura Sakaki||The Greek letter sigma Σ||VIdeo Game Controller||Shockwave|
|Touko Arareya||The infinity sign ∞||Conductor's Baton||Explosion|
|Nijimi Anazawa||Spade ♠||Panties||Mind Control|
|Hiroko Shimozono||The asterisk sign ✽||Remote Controller||Causing Diseases|
|Rina Shioi||Diamond ♦||Hammer||Break Surface|
|Unknown||Degree ℃||Drum||Thermal Change|
|Unknown||Both sided arrow ⇔||Dice||Replication|
|Unknown||Circle ○||Water Gun||Petrification|
|Unknown||Female gender symbol ♀||Tie||Gender Conversion|
|Unknown||Asterism sign ⁂||Pinwheel||Wind Currents Creation|
It should be noted that there is an eleventh stick, which does not appear in the spaces of Kayo's original stick but was used by her at a time of importance in the series. She also used Alice's rewind but it is not known what ability it replaced.
|Unknown||Exclamation mark !||Syringe||3 Minute Amnesia|
|Alice Misumi||Roman numeral Ⅳ||Flip Phone||Rewind|
|Kosame Amagai||The letter Q||Box Cutter||Healing|
- The word "Kayo" translates to "Wonder" while "Komura" translates to "Calf".
- She was given a stick and the Slaughter Note by Nana.
- She made her debut anime appearance on Episode 6, although it was a cameo. She was one of the many people shown in the photographs.
- She and Aya Asagiri have similar traits:
- They both have a male character caring for them. Makoto Hinomoto for Aya and Takuma for Kayo.
- They are both the main protagonists of each story.
- They both made a friend who they became closer as the story progresses. Tsuyuno for Aya and Sakura for Kayo. In the former case they were actually long lost sisters.
- They both almost experienced rape, Aya was almost the victim of rape while Kayo's friend Takuma, was the victim of rape, though he was saved at the last minute.
- In Chapter 84, she used Alice's stick to save the other Magical Girls but it is not known what ability it replaced.
- Her birthday is on April 17th.