Rei is a middle-aged woman with an average height and build. She has straight shoulder-length white hair with rather long bangs over her face. Her face has round features, having mellow expressions in casual situations. Her tired-looking eyes are brown-gray with reasonably long eyelashes.
Wearing various civilian clothes, Rei favors plain colors and patterns, such as a yellow jumper and orange t-shirt.
Rei was once kind, caring, and loving towards Shoto Todoroki and in return, he loved her deeply. She would always support Shoto such as trying to stop her husband's mad training methods and encouraging her son to become the man he wants to be, indicating her selflessness.
However, the constant abuse that she received from her husband caused her to become mentally unstable, to the point that one day she finally snapped upon seeing Shoto's left side, which reminded her of Endeavor. This caused her to pour a kettle of boiling water she had near her over her son's face, burning him. She did not, however, do this out of hatred for Shoto, but rather due to her mental instability and it later reveals that after doing so, she immediately attempted to soothe her son's burns using her ice quirk, while hysterically apologizing to him and asking herself why she did it.
After staying at a psychiatric ward and being away from her husband, Rei has shown to have returned to her past kind, caring self. Upon meeting her son again, she apologized and smiled through tears after he tells her that he forgave her, and the two restored their loving relationship. She also receives visits from her other children, Natsuo Todoroki and Fuyumi Todoroki, and appears to receive small gifts from her husband, although she is yet to see him face to face out of fear.
Unnamed Ice Quirk: Rei's Quirk gives her the ability to generate ice. This Ice Quirk is presumably very powerful, given that it impressed Enji Todoroki enough that he wanted an offspring with a combination of this Quirk and his own. This Quirk also gives her a liking for cooler weather.
- (To her mother) "Mom...I know it's not right, but I can't do it anymore. The children, they're...like him more and more every day. And Shoto...his left side. Sometimes I look at him and hate what I see. I...can't raise him anymore. I shouldn't raise him..."
- (To Shoto Todoroki) "But you want to be a hero, right? That's fine. You're not... bound by his blood. Decide who you want to become. And be all you can be."
|22. That's the Idea, Ochaco||Absent|
|23. Roaring Sports Festival||Absent|
|24. Mad Dash and Knockdown||Absent|
|25. In Their Own Quirky Ways||Absent|
|26. Chase Down the Leader||Absent|
|27. Earth-Shatteringly Fateful Negotiations||Absent|
|28. Strats, Strats, Strats||Absent|
|30. Cavalry-Match Finale||Absent|
|31. The Boy Born with Everything||Flashback|
|32. Smile, Prince of Nonsense Land!||Absent|
|33. Shinso's Situation||Absent|
|34. Victory or Defeat||Absent|
|35. Battle On, Challengers!||Absent|
|36. Bakugo vs Uraraka||Absent|
|37. Midoriya and Endeavor||Absent|
|38. Todoroki vs. Midoriya||Absent|
|39. Shoto Todoroki: Origin||Flashback|
|41. Fight On, Iida!||Absent|
|42. Final-Match Time||Absent|
|43. Todoroki vs. Bakugo||Absent|
|44. Relaxing Day Off||Debut|
|45. Time to Pick Some Names||Absent|
|46. Bizzarre! Gran Torino Appears||Absent|
|48. Getting the Knack||Absent|
|49. Midoriya and Shigaraki||Absent|
|50. Kill'Em Dead||Absent|
|51. No, Knock it Off, Iida!||Absent|
|52. Hero Killer Stain vs. U.A. Students||Absent|
|53. From Todoroki to Iida||Flashback|
|54. Re: Ingenium||Absent|
|57. The Aftermath of Hero Killer Stain||Absent|
|58. Internship's End||Absent|
|59. Listen Up! A Tale From the Past||Absent|
|184. Japanese Hero Billboard Chart||Absent|
|185. Wing Hero: Hawks||Absent|
|186. Endeavor and Hawks||Absent|
|187. Flaming Roar! vs. Nomu: High-End||Appears|
|188. Your Father, the Number One Hero||Appears|
|189. Why He Gets Back Up||Absent|
|190. His Start||Absent|
|191. Dabi, Hawks, Endeavor||Absent|
|192. The Todoroki Family||Flashback|
|241. Do That Interview!||Absent|
|242. Have a Merry Christmas!||Absent|
|243. Off to Endeavor's Agency!||Absent|
|244. Recommended Reading||Absent|
|245. Rise to Action||Absent|
|247. Status Report!||Absent|
|248. One Thing at a Time||Absent|
|249. The Hellish Todoroki Family||Flashback|
|251. Just One Week||Absent|
|252. The Unforgiven||Mentioned|
- Rei is one of Shoto's driving forces to become a hero one day, which is shown in a flashback when she inspires him while the two of them are watching an All Might TV interview.
- According to Shoto, he spends most of his free time with his mother in the hospital.
- Rei's name contains the kanji for "cold" (冷?).
- ↑ 1.0 1.1 1.2 My Hero Academia Manga and Anime: Chapter 187 (p. 1-5) and Episode 88, Rei's name is revealed.
- ↑ 2.0 2.1 2.2 2.3 My Hero Academia Manga: Chapter 39 (p. 10-16).
- ↑ My Hero Academia Manga: Chapter 53 (p. 15).