Question: Mizuto Hirota competes in Featherweight division, which refers to what weight class?

Context paragraphs:
Mizuto Hirota: Mizuto Hirota (廣田瑞人 , Hirota Mizuto , born May 5, 1981) is a Japanese mixed martial artist currently competing in the Featherweight division of the Ultimate Fighting Championship.  A professional competitor since 2005, he appeared in the Japanese MMA event Dynamite!!  2009 event and has also competed for Shooto and Strikeforce.

Romie Adanza: Romie Kris Adanza (born August 1, 1979) is an American Muay Thai kickboxer who competes in the flyweight division.  Known for his good boxing skills and aggressive fighting style, he began his career as a featherweight, winning the WBC Muaythai International Featherweight Championship before dropping down to bantamweight and having even more success by taking the WBC Muaythai national title and the IKKC International Super Bantamweight belt.  After one final weight class change down to flyweight, he won another WBC International crown before becoming the MTAA World Flyweight Champion.

Weight class (boxing): A weight class is a measurement weight range for boxers.  The lower limit of a weight class is equal to the upper weight limit of the class below it.  The top class, with no upper limit, is called heavyweight in professional boxing and super heavyweight in amateur boxing.  A boxing match is usually scheduled for a fixed weight class, and each boxer's weight must not exceed the upper limit.  Although professional boxers may fight above their weight class, an amateur boxer's weight must not fall below the lower limit.  A nonstandard weight limit is called a catch weight.

Taekwondo weight classes: In taekwondo, a weight class is a standardized weight range for taekwondo practitioners.  The upper weight limit for each class is the lower limit of the next highest class.  A taekwondo gyeorugi is usually scheduled for a fixed weight class, and each practitioner's weight must not exceed the upper limit.

Brian Ortega: Brian Ortega (born February 21, 1991) is an American mixed martial artist currently competing in the Featherweight division of the Ultimate Fighting Championship.  A professional competitor since 2010, he has also formerly competed for the RFA, where he was the Featherweight Champion.  He currently fights in the UFC featherweight division.

Mike Wilkinson (fighter): Mike Wilkinson (born September 15, 1987) is an English mixed martial artist who formerly competed in the Featherweight division of the Ultimate Fighting Championship.  He competed on .  Wilkinson competes in the featherweight division of the Absolute Championship Berkut

Featherweight (MMA): The featherweight division in mixed martial arts refers to different weight classes:

Floyd Mayweather Jr.: Floyd Joy Mayweather Jr. (born Floyd Joy Sinclair; February 24, 1977) is an American professional boxing promoter and former professional boxer.  He competed from 1996 to 2007 and 2009 to 2015, and made a one-fight comeback in 2017.  During his career, he held 15 world titles in five weight classes and the lineal championship in four different weight classes (twice at welterweight), and retired with an undefeated record of 50–0, surpassing Rocky Marciano's record of 49–0.  As an amateur, Mayweather won a bronze medal in the featherweight division at the 1996 Olympics, three U.S. Golden Gloves championships (at light flyweight, flyweight, and featherweight), and the U.S. national championship at featherweight.

Professional wrestling weight classes: In professional wrestling, a weight class is a standardized weight range for the wrestlers.  The top class in almost every promotion is heavyweight, but super heavyweights exist.  Weight class matches in modern-day American professional wrestling are rare, but weight class championships still exist.  However, Japanese professional wrestling, Mexican wrestling and British wrestling use the weight classes more seriously.

Lineal championship: In combat sports where champions are decided by a challenge, the lineal championship of a weight class is a world championship title held initially by an undisputed champion and subsequently by a fighter who defeats the reigning champion in a match at that weight class.  In professional boxing, the lineal champion is informally called "the man who beat the man".  Champions recognized by sanctioning bodies such as the World Boxing Association (WBA) or World Boxing Council (WBC), or the Ultimate Fighting Championship (UFC) may vacate their title voluntarily, or be stripped of the title for breaching the sanctioning body's regulations or contracts.  There will thus be a breach of continuity in the list of sanctioned champions which the lineal championship is intended to prevent.  However, there is no single canonical list of lineal champions at any weight class, because there is no agreed upon method of determining the starting point for each lineage and conflicting opinions on what to do when the current champion retires or moves to a different weight class, although there is agreement that any stripping of a title be discounted.

Supporting paragraphs: Mizuto Hirota Featherweight (MMA)
Answer: different weight classes