When a succubus comes to the home of a man, ready and rarin' to suck out all his life energy, she runs into an unexpected problem - the man is depressed, and feels no sexual desire whatsoever. Not one to be daunted thus, the succubus decides to move into the man's home and take care of him, in the hopes of being able to get it on with him later. So begins Yuuutsu-kun to Succubus-san by Sakamegane, a Slice of Life manga in which a Succubus takes care of a man with depression and, slowly but surely, helps make his life better.
The primary characters are the succubus, who takes the name of Sakuma, the depressed Yuu, Tsuguna Eru, a well-meaning but insensitive angel, and Metasuke, Sakuma's kouhai.
Yuuutsu-kun to Succubus-san provides examples of:
- The Eeyore: Yuu starts the series in a state of serious depression because of how badly he's been overworked. When Sakuma makes him leave that job, he spends most days literally lying around doing nothing, or occasionally sitting and watching the outside through his window. Sakuma's entire goal is to help him get better, and there are consistent signs that he values her presence in his life. Yet, even as he improves, Sakuma can't imagine what Yuu smiling would look like. When she tries it comes out as a blurred image.
- Going Commando: Eru's top is a shirt with long sleeves that only goes down past her breasts. A long gown covers the rest of her body from the stomach down. In a moment of A-Cup Angst, Sakuma flips her "boob skirt" and unwittingly discovers that Eru doesn't wear anything underneath. The humiliation of the moment leaves Eru huddled in a fetal position next to, and just like, Yuu.
- Home Nudist: Being a succubus, Sakuma typically wears as little clothing as she can get away with. When at home, she wears a pair of underwear and small pasties over her breasts. However, Sakuma dresses much more modestly when she leaves the house to go to work or tend to an errand.
- Horny Devils: Sakuma is a succubus. The series opens with her trying to seduce Yuu so she can drain his life energy. His depression and subsequent lack of sexual urges puts that plan to an end. Fortunately, she doesn't need to devour life force to survive, but it is preferred. She describes the act as feeling like she's wringing three hundred million lives out of her victim, adding "like a bunch of tadpoles."
- Inkblot Test: Chapter 7 features a variation called the Baum Test. Rather than the standard inkblot, the test involves the patient drawing a tree, usually a baum per the name of the test, and determining information about the patient from the drawing. Yuu draws a bare stump. Just as Sakuma is lamenting that she can't work anything out about Yuu from that, she notices something on the horizon line: two small dots that, on closer inspection, are Yuu and Sakuma holding hands. She declares the drawing perfect.
- Innocently Insensitive: This is Eru's big issue when it comes to dealing with Yuu. All she ever really tries to do is encourage Yuu to do his best, or otherwise offer empty platitudes. In contrast, the very first chapter shows Sakuma reading up on depression and discovering that telling people who tend to put blame on themselves to "do your best" is the exact opposite of what's best to do, and one should instead tell them "you did your best."
- Maintain the Lie: Sakuma wants to look good in front of her demon kouhai, Metasuke. The problem is, where Metasuke is regularly draining men a la the demon and succubi way, Sakuma hasn't really done anything except care for Yuu, whose lack of urges make using him impossible. She asks Yuu to play along if Metasuke visits, which she does almost immediately. When Metasuke notices the lack of sexual desire in Yuu, he says he needs "10 more until the daily quota is met", which Metasuke interprets as Sakuma drying him up the moment he gets any desire, properly impressing her.
- No Name Given: The characters aren't given proper names until chapter 34. In fact, Metasuke is the fourth character introduced but the first one to be formally named. In chapter 34, however, Eru lampshades it when learning Sakuma's chosen alias, at which point she gives her own full name, and Yuu reminds them of his name, in case anyone forgot or didn't know.
- No Poker Face: Eru is unable to maintain her expression in any way during a game of Old Maid with Sakuma. Sakuma, being a demon, is much more proficient than Eru. However, while her Poker Face is excellent, her Poker Wings leave much to be desired, as Eru's attempts to pick a card elicit either dead silence or frantic flapping.
- Only Known by Their Nickname: The succubus's name, Sakuma, is an alias. According to her, succubi keep their real names close to the chest, even among relatives. The way she explains it sounds like knowing a succubus's true name is a big deal, but the intense blush she gets just from Yuu calling her "Sakuma-san" implies it's more the intimacy behind being on a First-Name Basis.
- Parodies for Dummies:
- Chapter 33 shows Sakuma gave Eru a book to read on dealing with Depression titled "Even a Monkey Could Do It: How to Heal a Heart". She learns enough from it to call Sakuma out on forcing Yuu to leave his job, as the book suggests serious life changes can cause exactly the kind of stress that should be avoided. Sakuma acknowledges this and explains she felt Yuu's case needed more drastic measures. Eru then immediately tries to use the book to tell Yuu he's supposed to be working, prompting Sakuma to tell her she's failed as a monkey.
- On the back of the "How to Heal a Heart" book is an advertisement for "Even A Cat Could Do It: Quantum Mechanics".
- Porn Stash: In chapter 9, Yuu pulls out some books that fell from the bookshelf. They have titles like "Pure Pure Love", "Super Pure Love", and "First Love". Sakuma is horrified and embarrassed, as she'd hoped she'd found a good hiding place.Sakuma: It would have been fine if they were erotic books! I'm supposed to be a demon you know!? For succubi, consuming anything that doesn't provide nutrition such as pure love is the same as being a pervert! Yeah, that's right! I'm a pervert for romance novels! Got a problem with it!?
Yuu: Everyone has their curiosities while growing up...
Sakuma: Don't give me that kind of follow up!
- Pretty Freeloaders: Inverted. Sakuma calls herself a freeloader, but she's the one who works to bring in money. She takes on the obligation after making Yuu leave his job due to how it overworked him to the point of intense depression. They're able to get by on what she makes on top of Yuu's severance/retirement pay.
- Sempai/Kōhai: Another demon that occasionally pops in is Sakuma's kouhai from school, Metasuke. She looks up to Sakuma, and doesn't realize that Sakuma hasn't gone after any other men than Yuu, while she manages several a day, despite encountering people like Yuu who are overworked/depressed to the point that they have no sex drive at all.
- Shipping Torpedo: Sakuma's boss at the "Pandemic" bakery. She misinterprets her relationship as an abusive one in which Yuu makes Sakuma do all the work while he just lazes about the house. In one instance, she goes so far as to offer Sakuma tickets to an amusement park with an urban legend that it breaks up couples and actively shuts up a bystander who tries to mention said legend. The plan fails because Sakuma decides Yuu's in no condition for such a trip.
- Teru-Teru Bōzu: In the first chapter, Sakuma decides to make a Teru-Teru Bōzu during a bout of gloomy weather. She draws the face on it to resemble Yuu. This, combined with the realization that Teru-Teru Bōzu are hung by the neck, prompt her to immediately abandon that option and suggest sacrificing a goat instead.
- Your Normal Is Our Taboo: Sakuma's idea of what is considered good and proper is noticeably inverted. To her, displays of pure love are the height of perversion, while watching porn is considered a wholesome family activity. When visiting a shrine with Yuu during New Year's, she is absolutely shocked to see a young couple walk past them holding hands.Sakuma: There must be something wrong with their brain if they can simply walk outside while holding hands like that! (to herself) That's what two people holding hands look like... wow... it's the first time I've seen it... (out loud) In the Demon World, that kind of stuff would be rated R... they'd probably censor the hands with mosaics even... it's totally against the Demon Ethics Association...