Otogi no Machi no Rena

Otogi No Machi No Rena is an Ecchi manga by Hattori Mitsuru, which is set in the town of Otogi, where our heroine, Rena, lives a peaceful life between school and athletics, until she suddenly has unsually intense surges of lust and it goes from there. She can't always suppress her urges, so that the resident nerd and lech, respectively, soon catch on; while the first wants to help her and get in her pants, the latter just wants to get it on with her. Rena soon finds out that these surges come from little hairy creatures called Kegari Chota, which have possessed her and she is a idol and mother figure to them (literally) which they protect at almost any price or circumstance.

This Manga provides examples of:

 * All Guys Want Cheerleaders: Ogata, Jirou, his brother and the guy that works at the gym all want Rena, a cheerleader.
 * Badass Adorable: The Kegari Chota.
 * Berserk Button: See the Oh Crap entry down below.
 * Butt Monkey: Ogata.
 * Also, Rena. Going into heat when you really don't want to can NOT be fun.
 * Demonic Possession: By HAMSTERS!!
 * Dirty Old Monk: The High Priest.
 * Dude, She's Like, in A Coma:
 * Ecchi: A lot. Sometimes to egregious extents.
 * Genki Girl: Rena. And her little sister, Mikoto, is even Genki-er.
 * Green-Eyed Monster: Mikoto is jealous of Rena because she keeps trying to catch a Kegari Chota but they like her sister better. Yes, Mikoto's a little simple.
 * Horny Devils: The Kegari Chota cause high levels of desire in the possessee which can only be quelled by masturbation or sex, which creates more hamsters. Rinse and repeat.
 * Implacable Man: The Kegari Chota can follow you anywhere, can catch up to anything and are Nigh Invulnerable. So, Rena never gets rid of them.
 * Jirou, when his Piko Piko meter gets above 80%.
 * I Was Quite a Looker: Ogata's grandma. The priest inverts this by looking better now than he did in youth.
 * Killer Rabbit: Or killer demon hamsters.
 * Ms. Fanservice: Rena, unsurprisingly.
 * Oh Crap: Whenever the Chota think Rena is molested when not in heat, their eyes and antennae glow, antennae and hair stand straight up. Don't be close to whereever they are then.
 * Otaku: Ogata, though his field isn't clarified.
 * Parents in Distress: The hamsters jump to Rena's aid when she's not in heat.
 * Plot Armour: The thing that protects Jirou and his brother from being beaten up by Rena.
 * Ridiculously Cute Critter: The Kegari Chota are so cute that it hurts.
 * Virginity Makes You Stupid: Mikoto actually wants to get the Kegari Chota to hang around. Also, Rena because she hasn't turned Jirou in to the police.
 * Wham! Line: The end of chapter 37.
 * Why Don't Ya Just Shoot Him: Or kick him until the testosterone glands in his testicles stop functioning? Or simply turn him in and let the police deal with Jirou?