She is Ichiko's classmate who bears a deep resentment towards her.

At the expense of the people and things around her, Sakura has absorbed so much "happiness energy" that she has caused an energy imbalance in the world. In order to return balance to the world, the Poverty God, Momiji, sets out to take away Sakura's ability to absorb this energy. Will Momiji be able to put a stop to Sakura's absorbing abilities, or will the God succumb to her happiness? 
(Source: FUNimation)

Sakura Ichiko is a 16 year old girl who leads a charmed life and is blessed with beauty, brains, and health. She has an abundance of “Happiness Energy”, which can make people happy, but at the cost of absorbing all the “Happiness Energy” from her surroundings. She has caused the energy balance of the world to become unbalanced and because of this, she becomes the target of a Poverty God named Momiji. Momiji goal is to remove Ichiko’s power of absorbing other people’s Happiness Energy and to return all the energy she has taken to its rightful place. 
(Source: Akiba-station)
 
Included chapters: 
Volume 6: Binbougami Ga!' Is! 
Volume 6: You Binbougami! 
Volume 10: Extra Round: You'll Put Them in the Most Delicious Place Of All 
Volume 11: Extra Round 1: It's Better to Grow Up Slowly 
Volume 11: Extra Round 2: Did Somebody Call for a Prince!!! 
Volume 13: Extra Round 1: I'm Glad the Three of Us Could Come 
Volume 13: Extra Round 2: A Pet's Misbehavior is the Owners Responsibility You Know 
Volume 16: Art Book Extra Round: Come Here 
Oneshot: not included in any volume, in was published in Weekly Shounen Jump to promote the main series, which ran in Jump SQ

Akane Tange