Due to the combination of Toru's lack of screen-time (as she is a background character), and either character's closer relations with other classmates, Toru and Katsuki do not interact too commonly. However, thanks to their seating arrangement in class, which has Tooru sat in front of Katsuki, they're commonly seen near each other, especially in full class shots. Additionally, Tooru is known to have a fondness for boys she deems attractive, and she occasionally comments on the appearances of the school's 'ikemen', or 'pretty boys', including Katsuki.
After defeating Pixie-Bob’s 'Earth Beasts', and making their way to the site of the Training Camp, it's up to the students to prepare their own dinners. Katsuki takes the role of cutting up vegetables, which he proves a talent for knife-wielding with. As he chops, Toru stands by his side to assist with this task, rather than starting the stove with her close friend Mina, and class ‘heartthrob’ Shoto.
The Training Camp is cut short after Katsuki's kidnapping by the LoV. After his rescue, U.A implants a dorm system in their school in hopes to prevent any more situations like Katsuki's by keeping the students all in one place. Prior to allowing the students to explore the dormitory, however, Eraserhead harshly scolds the students, going as far to say that he would've expelled everyone with the exception of Katsuki, who was kidnapped, Toru, and Kyoka, who were knocked out by the villain Mustard's gas attack. Everyone becomes downtrodden by this, including the usually sunshiney Eijiro. In an attempt to distract Eijiro from his sadness, as well as his other classmates, Katsuki drags Denki behind a nearby bush to have him overuse his quirk in a matter of seconds, and enter his ‘Whey/Dumb Mode’. Toru watches him from the front view as he pulls this stunt.
As both hearoes haven't interacted that much through the series, this ship is rare as considered a crack pairing. Also it's because Toru is a background character unlike Katsuki, making him spend more time with other more girls that have more screentime, such as Ochako (Kacchako). Due to their heavily differing stances in the series, lack of canon interactions and the shadow cast by more popular ships, such as KiriBaku or BakuDeku for Katsuki and OjiToru for Toru, BakuToru is not particularly popular, or even known within the MHA/BNHA fandom. However, like any ‘rare-pair’, certain aspects, whether they be similarities or differences, draw decent attention to the pairing.
Right now there's only 20 works for Katsuki and Toru on the AO3.
- Tooru holds Seat 16, while Katsuki holds Seat 17, and sits behind her.
- Both characters have well-known friendships with Mina.