Shana is the main female protagonist and the titular character of Yashichiro Takahashi's light novel series Shakugan no Shana, and its anime adaptaion by J.C. Staff.
Shana is quite possibly one of the most storied competitors ever to play in the major tournaments. Her history in the saimoe contests can be dramatized like a protagonist in a sports anime: a contender who consistently performs well, but for some reason, always fizzles out in the end, giving the protagonist so much angst to work on. After so many tournaments ended with suffering and despair, the protagonist attempts to win the championship for what could be their last time in doing so, and this time, they finally succeed, completing their redemption arc and cementing themselves as a champion -- forever.
Is either rich, or possesing supernatural powers, or both.
Most importantly: the character is a tsundere, the main character's love interest, and voiced by Rie Kugimiya, who is often typecast to this kind of roles.
This type of character proved very popular with anime fans, and by 2006 Shana blazed a trail (pun intended) in the Saimoe Tournaments, reaching the semi-finals of both Japanese and Korean contests in her first year. She would establish a constant presence in both of these tournaments, always appearing in the latter rounds for the better parts, but unfortunately, she would end up never winning any of them.
Ever since the arrival of the spin-off (and later a major-tier one) contest International Saimoe League, Shana has developed a reputation for being a fan-favorite character who also has a substantial amount of opposition, and hence, she has built a long history of broken promises and heartbreaking defeats.
Among these harrowing losses includes one of the closest ever finals match in a major tournament: a loss against Hinagiku Katsura in Korea's 2007 edition by a score of 2013-2015, a vote difference of just 2 votes. Hinagiku would later steal Shana's championship again in the same fashion in ISML 2009, torturing the Flame Haze by a score of 2106-2117, a margin of just 11 votes. Shana would later return to the finals two years later, only to lose in a heated match-up against the super-charged Mikoto Misaka by a score of 8052-9208.
Shana continues to perform decently well in ISML's Nova / Stella Era, reaching the postseason from 2012-2014, but her chances for Tiara contention have been sidelined in favor of other girls from more popular series; and she entered a state of decline in 2015 because she failed to make the postseason that year.
All is not lost however, as the Nova / Stella era divisions were merged, a new tournament format started to emerge in ISML 2016. The year saw a drop in voters, making the 2016 edition's numbers on par with ISML's early years. Shana's strength was reignited in this year, winning the Amethyst necklace (her first in 5 years) and finished as the 2nd seed in the regular season. In the final group stage, she finished first in Group B, before defeating Rin, Yukino, and surprise finalist Illya in the playoffs. After a decade of chasing major championships, she finally attained the most prestigious prize she rightfully deserves: the 2016 Heavenly Tiara.
Shana is the only girl to have the most finals appearances in all of the major tournaments (four), with three of them being losses (KBM 2007, ISML 2009, and ISML 2011) and the last one being a win (ISML 2016).
Shana currently holds the record-most number of pure necklace rounds won in International Saimoe League, winning a total of seven (7)necklaces. The majority of them came from the double-elimination era (2008-2010) which includes three wins from 2010, the most in a single year. She is the reason why from 2011 onwards, girls can't win multiple necklaces on the same year.
If Nova and Stella Circlet gems are counted, then she is tied for first with 7 gems won, together with Kanade Tachibana (2 circlets) and Mashiro Shiina (1 circlet).
Shana has the ISML's record of won exactly 300 matches and is the first contestant to ever reach that many wins.