2013–2015: Viral photo, hosting, acting
In 2013, Hashimoto gained national attention when a photo of her taken at Rev. from DVL's live performances from November 3 to 4 went viral on 2channel and Twitter. Praised for her natural beauty, she was given titles such as "beyond cute local idol", "beyond angelic idol", and "a talent appearing once in a millennium." A post on Naver exceeded 550,000 views by November 7, 2013, and the server for her agency's official website was temporarily down due to excessive access. In the corner of NHK's late-night news program "News Web", "Tsubuyaki Big Data", which introduces trends on Twitter and Google Trends, showed that the number of searches on Google had risen rapidly, and had also spread to Chinese users. The photo was also mentioned on Good! Morning (Asahi TV) and Mezamashi TV (Fuji TV). According to her agency, in response to her viral photo, there was a flood for offers from TV commercial appearances and interviews.
Additionally, Kadokawa representative director Shinichiro Inoue who saw the photo "fell in love at first sight" and sent an email to his company saying "I want to make a movie with her"; the next weekend he went to a live performance held at a train station in Fukuoka and, struck by the excitement of the stage, said "I definitely want you to star in my next movie", thus casting her in Sailor Suit and Machine Gun: Graduation; this story was revealed at the press conference for the production of the movie.
Hashimoto herself said "I don't know even one millimeter of goodness" of the photo that triggered her breakthrough. She said, "there was frustration, and maybe I was showing it on my face".
In April 2014, she was selected as a regular on the variety show Minna no Seishun Nozokimi TV Teen!Teen!, becoming the host of the program alongside Naoki Matayoshi and Yuju Ayabe of the comedy duo Peace. Hashimoto, who became a high school student, said, "I'm excited for the start of my first regular program. I'm nervous because it's my first time as a host, but I'll do my best, so please watch it!". Additionally, she was appointed as the MC of Daiichi Kosho's online karaoke "DAM Channel", welcoming various artists as guests and serving as the 11th and also the youngest MC in the program's history. In the May issue of the fashion magazine Popteen which was released in April, she made her first cover appearance and also featured on the cover for five pages. She also featured on the cover and opening gravure of Weekly Young Magazine, released at the same time, which was her first gravure activity. In July, she made her first appearance in a nationally broadcast serial drama with Fuji TV's Water Polo Yankees. Producer Ryota Fujino said, "Having an overwhelming presence and a sense of transparency, I am confident that she will move the characters and the story." She costarred with Yuto Nakajima in Episode 6. Hashimoto said, "Yesterday and this morning, my hands were sweaty, and I was really nervous." When asked if there was a role that she would like to try in the future, she said, "I haven't done anything yet, so really anything can 'come on'!". In August, she was featured on "Too angelic MC in a town that is too exquisite! Full summer in Sacas SP" which was a live broadcast special program on TBS. In November, she was selected as the "2014 Hit Person" by Nikkei Trendy alongside actor Tsuyoshi Muro, who acted as the commentator for the "Best 30 Hit Products of 2014" and the facilitator at the presentation.
In March 2015 she appeared in the live action of Assassination Classroom as Ritsu, an autonomous thinking fixed gun battery. She appeared as the host of the variety show "Rev. from DVL's Afterschool" and "Magic that changes the world! Algorithm Institute".
In June, at a press conference to announce the production of the movie Sailor Suit and Machine Gun: Graduation, a "spiritual sequel" to Sailor Suit and Machine Gun, held at Shinagawa Prince Hotel, it was announced that she would play the role of the main character, the fourth head of the Medaka group, a high-schooler who was a former teenage delinquent and becomes the boss of a yakuza, Izumi Hoshi. Hashimoto, who was starring in the work for the first time, said, "This is a work performed by famous actress seniors, so I want to act like Kanna Hashimoto, not like someone, but like Kanna Hashimoto." "I would like to seal the film and face the filming with courage and a positive heart," she said. Also, when asked about her future goals, she said, "I want to become an actress who can play a wide range of roles without being bound by one image." The trailer, which was released in December, revealed that she would be making her solo debut with the theme song "Sailor Suit and Machine Gun", a cover of the original by Hiroko Yakushimaru and Masami Nagasawa. Starting February 3, 2016, the music video for the theme song began distributing exclusively on U-Next for one week. From the 11th of the following week, it would be available publicly on the "Rev. from DVL Official Channel". Also, on the 8th, a public recording on NHK General Music Japan was held. Hashimoto, who would be performing solo, said, "I am very nervous to sing to everyone on such a big stage for MJ (Music Japan), which everyone dreams of appearing on." "But I'm not alone, I have everyone involved in Sailor Suit and Machine Gun: Graduation." On the 20th, she performed in the theme song on Fuji TV's Music Fair. The song ranked 1st on the Oricon Daily Chart. It also reached number 11 on Oricon's charts and charted for 7 weeks. On the first day of the movie's release on March 5, Hashimoto said, "Thanks to everyone involved in this movie, I've come to love movies and my job as an actress. I feel like I've taken my first step as an actress this time. Sailor Suit and Machine Gun: Graduation Izumi Hoshi will be graduating today, but I will take everything I learned from this work as an important lesson. I will also start walking towards new works and roles", sending a message of gratitude and determination to fans and related parties. In 2015, a web poll conducted by My Navi Student declared her the Cutest Idol from both the men's choices and women's choices list.
