When viewed from the side, if you can see the crease under the breast where it returns to the torso while the nipple is still concealed, you are seeing Sideboob.
Whereas Navel-Deep Neckline is all about showing as much of the area between the breasts as possible, this trope is about exposing the outer sides, roughly from the armpit to the nipple. There is a variant where the nipple is intentionally concealed by the arm, the hand, or the legs, and occurs frequently in topless fashion photography.
Bonus points if combined with Navel-Deep Neckline. A staple aspect of Vapor Wear. Commonly goes hand in hand with Naked Apron, though not at all restricted to it. Compare with Underboobs.
Examples:
- Allegory of the Four Seasons (Manfredi): Summer is looking at the viewer over her shoulder. Since she is bare-chested, the side of her boob is in full view, bare nipple included.
- Bleach:
- Soi Fon has customized her shihakusho to only cover the front of her chest due to her Shunko destroying the back and sleeves of whatever she's wearing, leaving the sides of her breasts exposed in the process, though the original run of the anime and media adapted from it censored this by having her wear sarashi underneath.
- Yoruichi's backless suit during her fight with Soi Fon sports this when she uses Shunko herself. Not to mention Kuukaku's outfit.
- My Hero Academia: Momo has it, but also a Navel-Deep Neckline at the last degree and a Sexy Backless Outfit. Well, it's literally two tissue strips.
- No Game No Life: Jibril has a big one.
- One Piece:
- In the seventh movie, Nico Robin briefly sports a gorgeous blue dress which contains some side boob.
- Yamato tears off the sleeves of his kimono when he reveals himself, leaving the sides of his breasts exposed. Humorously, a fan once asked for the author to draw an anthropomorphization of Yamato's sideboob, and he drew a fat man with half of his body draped in a sheet.
- Tokkô: Sakura shows some side boob through her tank-top in a few scenes.
- In the original Yu-Gi-Oh!, Mai's Harpie Lady monsters wear what is little more than a slingshot bikini.
- Supergirl: In Adventure Comics #408-409, Kara wore a backless costume
◊ which showed some side boob.
- In American Reunion, Stiffler excitedly points out that he can see this when ogling an attractive girl in the beach scene.
- Machete: Agent Santana Rivera has the naked variant in her Shower Scene.
- Blue Peter presenter Zoe Salmon became the first BP presenter to go topless in the history of the show, and quite possibly the history of BBC childrens' broadcasting. This wasn't even with any high-minded purpose, such as education or art. The presenters were reproducing iconic images from the James Bond movies and Zoe did the one where the girl is covered in gold paint. Zoe was topless in sideboob pose and a combination of hair and right arm covering the contentious bits.
- The Exorcist (2016) Casey´s dress in episode 3.
- On an episode of The Late Show with David Letterman, the audience (and later all of Manhattan via the Jumbotron) gets a quick shot of Drew Barrimore's side boob, while Birthday Boy Letterman gets to enjoy the full effect.
- During his review of Q2, SF Debris refers to "television sideboob" regarding Jeri Ryan's nude scene.
- Miserable: Despite the fact that the character is played by the famously busty Pamela Anderson, and the video heavily indulges in Fanservice and Male Gaze, the video forgoes showing off the giantess' cleavage by putting her in a bikini with a more sporty design with a top that's more like a sports bra than a typical bikini. Instead, the video has several shots of her side boob, especially when she stands up and starts swaying to the song.
- Morrigan's starting outfit in Dragon Age: Origins demonstrates sideboob. Ditto her uber-clothes that you get for completing her personal quest.
- In The Elder Scrolls V: Skyrim, there are a few outfits. The most noticeable is the Ancient Nord Armor, Action Girl Aela the Huntress wears. Later on in a certain guild quest line, the Player if playing a female character can craft the same armor. It is also seen on draugr that were once women in life.
- In God Eater Burst, Sakuya's spaghetti-strap crop top leads to this look.
- In Resident Evil 6, Sherry Birkin gets captured by N.G.O. Superpower Neo-Umbrella. Six months later she wakes up in a Stripperiffic patient's outfit that includes this.
- Higurashi: When They Cry: Hanyuu has one on a splash page of the manga-adaptation.
- Umineko: When They Cry: Gaap's dress is an exaggeration of a Sexy Slit Dress where the opening is on the left side instead of the front and is only held closed by a bow, showing both the side of her breast and a lack of panties.
- In a Karate Bears dream sequence, a lady with sideboob rides bareback.
- The Whiteboard: As part of the 2012 April Fools' Day comic, the audience is treated to a Shower Scene with Pirta,
who's turned so that only the side of a breast is showing, with fur covering other details of her nudity.

