It centers around the relationship between Ordinary Highschool Student Kōichi Mizuki and the giant prince Caius Lao Vistaille, who has summoned Kōichi to his world to be his bride and bear his children.
As future ruler of Tildant, it was Caius's duty to wed a fertile bride and provide the kingdom with an heir. However, when an oracle prophesied that great misfortune would befall the country if Caius ever were to marry a resident of his world, his original marriage was cancelled. Caius searched day and night for an old ritual that would allow him to summon a being from another world to be his bride, so he could have both the throne and his love.
Kōichi Mizuki is in his third year of high school and envied by his classmates for his good looks, athleticism and tall stature. One day, while in the middle of masturbating, he's suddenly transported to another world and approached by a handsome giant who calls him his wife.
On March 18, 2020, it was announced that the series would be adopted into a television anime by Studio Hōkiboshi and Comet Company. The first trailer was released on June 19, 2020, with the anime premiering on July 5, 2020. A censored version of the anime, cutting out all the sexually-explicit content, was broadcast on Tokyo MX, Youtube and NicoNico, while a non-censored version can be watched on the digital distribution platform ComicFesta Anime.
The Titan's Bride provides examples of:
- The Ace: Koichi. In his own world, he was a star athlete, the captain of the basketball club and immensely popular with the ladies.
- All-Loving Hero: Koichi is a very kind young man who can't stand the thought of causing trouble for others. In Chapter 22, he stops Caius from killing Baro (who had previously kidnapped and molested him) because he can't bear the thought of someone getting in trouble or even dying because of him.
- Ambiguously Brown: The giants all have a noticeably tan skin tone compared to Koichi. Koichi immediately recognizes Caius as a foreigner based on that alone.
- Amicable Exes: The only reason why Caius and Medina's engagement got dissolved was because of the oracle's prophecy. Even long after they broke off their engagement, there's no hard feelings between the two and they both still deeply care for one another.
- Beastman: The country of Forbas is made up entirely of bipedal, anthropomorphic animals who are capable of speech and just as intelligent as the other races.
- Bowdlerize: Even the uncensored version of the anime cuts out a lot of the lewd stuff present in the manga.
- The manga had a scene of Koichi's underclassman pulling down his pants to complain about how well-endowed Koichi is compared to him. This got cut out of the anime entirely and is instead replaced with a segment showing Koichi and his team playing basketball.
- In the manga, Koichi is transported to Tildant while in the middle of getting himself off. Right into the middle of a crowd. Caius even makes a point of commenting on how small Koichi is and how cute he finds it. In the anime, Koichi is just lying on his bed when he gets transported and it's just Caius who greets him when he arrives.
- The anime cuts out the rather suggestive massage Caius gives Koichi in chapters 4 and 5 of the manga. Oh, and the sex that happened after.
- Conveniently an Orphan: Both of Koichi's parents are subject to Death by Origin Story. This was likely to mitigate the obvious Fridge Horror that would come from the resolution to Koichi and Caius's 1 month trial dating: all evidence and memory of Koichi's existence is permanently erased from the timeline of his old home world so he can live happily ever after with his Isekai husband.
- "Do It Yourself" Theme Tune: The English version's opening song is performed by Edward A. Mendoza (Koichi) and Kiba Walker (Caius).
- Fisher King: The leaders of each of the species are the conduits between the people and their god, and a nation will suffer if the leader fails to promote their species' fundamental trait. This is given multiple times as a reason Caius is considered unfit for the throne: first because prophecy forbids him from pairing with any of his own people, second because he isolated himself for years in search of a way around the prophecy.
- Gentle Giant: Caius is ginormous and intimidating, but he's a kind man with a big heart who would never intentionally hurt Koichi.
- Heroic BSoD: Chapter 77 reveals that the ominous prophecy that left Caius unable to wed anyone in his world had affected him more badly than anyone realized, as he spent at least a year in a depressed state and isolated himself from everyone else out of fear that he would bring harm to them.
- Hermaphrodite: One of the defining traits of the bird people, besides their wings, is that they have both male and female parts.
- Hot-Blooded: Naiad is passionate, not afraid to speak her mind, and pretty quick to anger, especially where her twin brother is concerned.
- Interspecies Romance: The story revolves around the romance between Koichi, a human, and Caius a giant. The anatomical differences is a major plot point and obstacle for the pair to overcome.
- The Immodest Orgasm: Koichi is not exactly what one would call quiet during sex, but it's not hard to see why he's unable to keep his voice down in bed.
- Impossible Task: The bridal quiz that Koichi has to undertake to prove his worth as Caius' bride requires him to figure out how to successfully hatch a stillborn child of the Hubbard royal family. At least, Naiad thinks that this is the case since all the people of Hubbard have been trying to have the egg hatch countless times for a whole year but to no avail, so there wouldn't be any reason to believe that Koichi, a human from another world, would be able to pull it off.
- Intimate Marks: Koichi gains one of these after deciding to stay with Caius and let his homeworld erase him from existence, marking him as Caius' true bride. In chapter 53, it's revealed that this mark will allow Koichi to tap into Caius' magic to use as his own.
- It Only Works Once: It's mentioned early on that using the summoning ritual requires a lot of magical power for the caster to successfully pull it off. And it turns out to be a dangerous gambit on Caius' end too, which is why he couldn't just send Koichi back home and attempt to look for another bride. Should he undo the ritual and send Koichi back to his world, it will end up taking not just more of his power, but also his life.
- Loophole Abuse: The oracle stated that Caius could never marry someone from Eustil, so he summons someone from another world to be his bride.
- Love at First Sight: Caius is instantly smitten with Koichi upon his arrival.
- Love Triangle: Seems to be set up with the arrival of Medina, Caius original bride-to-be. She acts incredibly antagonistic towards Koichi and it's heavily implied she still has feelings for Caius. It's completely subverted by chapter 9. As it turns out, Caius' sister noticed that Koichi wasn't feeling quite certain about the engagement and intentionally called Medina over to make Koichi jealous.
- Mistaken for Subculture: Koichi is frequently mistaken to be a dwarf by other characters since he looks too old to be a child Titan.
- Naughty Birdwatching: Rail did explain that he has to observe Koichi and Caius doing it so that he can be able to properly determine how he can help them with their sex life, though nonetheless, the trope still counts, especially when Rail starts to pleasure himself while watching the other two get at it.
- Non-Heteronormative Society: Eustil is pretty open about same-sex relationships, since the three different races are already pretty diverse. As Caius puts it, as a giant and a human, their races are already different, so gender is even less important. That being said, the later chapters show that some are not as approving of Caius and Koichi's relationship, though this has less to do with homophobia and more of their dismay at the fact that Caius' chosen bride is someone who cannot give him any heirs.
- Official Couple: Caius and Koichi are the manga's main couple. Heck, the series starts with them getting engaged, though only one of them knew of the engagement beforehand.
- One Head Taller: Try several heads taller. Caius positively towers over Koichi, despite Koichi being 5'11" (180 cm). Justified, since Caius is a giant (8'2" / 250 cm).
- Our Elves Are Different: Elves in Eustil represent the trait of curiosity and are known for being great scholars and scientists. They’re stated to have low sex drives except during their breeding season which is about a month every three years.
- Our Giants Are Different: The giants of Tildant look exactly like humans, only much bigger. They're a society based around the concept of prosperity: they farm, build, create art and encourage open love and, if possible, multiplying.
- Ret-Gone: Due to how summoning magic works in Eustil, the circumstances of Koichi's presence ends up poking a hole in the dimensional "wall" between his home world and Eustil that keeps the worlds separate and stable. It takes one month for it to repair itself, but it also means he would need to make a very important decision: leave Caius behind and return home, or form a contract that would also essentially rewrite history to where Koichi died young in his original home. He heavily considered going back home due to his sentimental ties with his mother and classmates, but ultimately stays with Caius.
- Running Gag: Koichi being so much smaller than his fiancé and the residents of Tildant is a frequent source of comedy.
- Second Love: Caius was engaged to Medina before the Oracle had their marriage contract revoked and he loved her just as much as he claims to love Koichi now.
- Sexual Extortion: Discussed as Rail makes it very explicit to Koichi that this trope is not his intention when he asks to conduct some research on the other's body. But given the nature of Koichi and Caius' request, Rail states that he will need to observe first-hand how Koichi reacts to various forms of pleasurable stimuli.
- Succession Crisis: It's not the Vistaille siblings who are fighting amongst each other for the throne; rather, it's the royal court who doesn't approve of Caius having a male bride and wishes for Naiad, Caius' younger sister, to take the throne instead. However, Naiad is against the idea and is even enraged that her brother has to face this problem.
- Surprisingly Realistic Outcome: Since Caius is a literal giant, it stands to reason that his... equipment would be just as massive. Koichi is terrified when he sees just how big it is and cries at the thought of having to sleep with him. This becomes a major plot point for the series as not being able to go all of the way actually impacts Caius's ability to channel and share his magical energy, a necessity for the future titan king. Both Caius and Koichi eventually seek out a member of the Long-Ear Tribe to see if there is a way to shrink Caius' size so that he can fit completely inside Koichi. Alternatively, after learning Koichi can tap into Caius' magic, he could utilize magic to increase his capacity.
- Token Human: Humans do not exist in Eustil, and the closest equivalent to humans in that world are dwarves, who are already a long-extinct race. Koichi is the only member of his race to live there.
- Trapped in Another World: Koichi, an Ordinary Highschool Student, is transported into the mystical world of Eustil.
- Trial-Period Dating: Ordinary High-School Student Koichi is summoned to another world called Eustil to be the bride of Caius, the prince and future ruler of Tildant, land of the titans/giants. Due to a prophecy that promised destruction should Caius marry someone from his own world, he had to summon someone from another and that just happened to be Koichi. Koichi is, naturally, against the whole idea. Caius then proposes that Koichi gives him a month to make Koichi fall for him; should he fail, he'll send Koichi back to his own world. Koichi accepts.
- Unlucky Childhood Friend: Medina was friends with Caius from early childhood and truly loved him. However, they were forced to end their engagement after the Oracle's prophecy. Slightly subverted as Chapter 9 reveals she eventually got over him and found a new fiancé.
- Wistful Amnesia: After Koichi is retgoned, his friends from his original world feel his absence, particularly his best friend Jin who sheds tears without knowing why, as well as Anzu, his crush who reciprocated his feelings.
- Wolfman: Baro is a wolfman of the anthropomorphic varieties.