ClariS is a Japanese vocal duo that has become one of the most recognized names in anime theme music. Formed in Hokkaido in 2009, the group was originally a pair of junior high school friends who started uploading cover songs to a video sharing website under the name Alice★Clara. Their popularity on the platform led to mainstream attention, and they made their major debut on October 20, 2010, with the single "irony" under SME Records. From the start, the duo adopted a unique and enduring practice of protecting their privacy by not revealing their faces publicly; instead, they are represented by official illustrated avatars and historically wore masks during live performances.

The group has undergone significant lineup changes while maintaining its core identity. The original members were Clara and Alice. In June 2014, Alice departed from the group to focus on her education. She was replaced by a new member, Karen, who joined later that year. Clara remained as the sole constant member through this transition. In late 2024, Karen announced her graduation from the group to focus on her marriage, concluding the second phase of ClariS. The group then entered a third phase in early 2025 with the addition of two new members, Elly and Anna, transforming ClariS into a three-piece unit.

ClariS is most celebrated for their extensive work providing theme songs for popular anime series. Their breakthrough came in 2011 with their second single, "Connect" (コネクト), which served as the iconic opening theme for the acclaimed series Puella Magi Magica. The song, written and composed by Shō Watanabe, became a signature track for the duo and solidified their status in the anisong genre. Their relationship with the Madoka Magica franchise continued for years; they performed subsequent theme songs including "Luminous" for the film Puella Magi Madoka Magica the Movie: The Beginning Story and "Colorful" for Puella Magi Madoka Magica the Movie: Rebellion. In 2025, ClariS was appointed the official Links Partner for the franchise, announcing a new song, "Links," and a self-cover of "Connect" titled "Connect -season 03-" to bridge past and future works.

Beyond Madoka Magica, ClariS has contributed music to a wide range of popular anime. Their debut single "irony" was the opening theme for Oreimo (My Little Sister Can't Be This Cute). They provided multiple songs for the romantic comedy series Nisekoi, including "CLICK" and "STEP". Other notable anime theme songs include "border" for Tsukimonogatari, "Hitorigoto" for Eromanga Sensei, "CheerS" for Cells at Work!, and "Koisekai" for Saint Cecilia and Pastor Lawrence. Their discography includes numerous successful singles and albums, such as the best-of compilation ClariS ~SINGLE BEST 1st~, which collects many of these anime tie-ups.

Musically, ClariS is known for a bright, synth-driven pop sound characterized by glistening melodies, upbeat productions, and the harmonious vocal interplay between its members. Their lyrics frequently explore themes of connection, friendship, and overcoming adversity, which resonate strongly with the narratives of the anime they accompany. Despite their visual anonymity, the duo built a strong live presence, culminating in their first concert at the prestigious Nippon Budokan in 2017, where they famously removed their masks in front of the audience for the first time. Through numerous hit songs and enduring partnerships with major franchises, ClariS has achieved significant industry significance as a leading anisong act of the 2010s and 2020s. Their signature song "Connect" has won awards, including a Newtype Anime Award for Theme Song Award, and is considered a classic in anime music history.