Omoi

is a shinobi of Kumogakure and a member of Team Samui. Several years later, he becomes the Fifth Raikage's bodyguard.

Personality
Omoi is a very cautious person and likes to think things through before acting, and as a result, gets lost in his thoughts quite often. He is more level-headed than his team-mate Karui, but often demonstrates a wild imagination and has a habit of exaggerating the end result of minor things (like when Karui threw a rock at him and he believed it would cause an avalanche and destroy Konoha) and likes to make fun of Karui's hot-headed personality with painful results. He also has respect for people who stand by their word, even if they are the enemy. He is a very intelligent ninja. In the anime, he was shown also to be very resourceful even under pressure. It has also been said by his team-mate, Karui, that he is rather pessimistic when he expresses his concern for Killer B. Nevertheless, he is capable of becoming deadly serious and exhibits great conviction when the situation demands it; having expressed disgust when he saw that Akatsuki was making Sai fight his brother and stepped in to prevent that from happening.

Appearance
Omoi is a young, dark-skinned Kumo-nin with short, spiky, white hair and dark eyes accentuated with lines curving upwards from the corners. He wears a dark outfit consisting of an overlong shirt with a hood, with red bandage hand guards, Kumogakure shin guards, and a black forehead protector along with a Kumogakure flak jacket. He is always seen with a thoughtful expression, as though always in deep contemplation and sucking on a lollipop. He also carries a long sword on his back.

Years after the Fourth Shinobi World War, Omoi's appereance and attire is mostly unchanged, though he now wears a smaller version of his village's flak jacket, which only covers his chest. He has also stopped wearing a forehead protector.

Abilities
Omoi is a very capable ninja, having been specifically chosen by the Fourth Raikage for certain missions. Even Kakashi Hatake commended Omoi's strength and went on to say losing him was a major loss. He is also very resilient, being able to continue to fight after being hit by many lightning attacks. Similarly, he is shown able to hold his breath for a noticeably long period of time while still fighting effectively. Omoi also collaborates effectively with his team-mate Karui, despite their constant bickering, using fluent attack patterns without communicating with each other during their brief scuffle with Team Kakashi. He also incorporates taijutsu in his collaborative attacks with Karui, being able to send Sakura Haruno flying a considerable distance away with a kick.

Kenjutsu
Omoi is highly proficient in kenjutsu. He uses a fairly long katana into his fighting style which was praised by Sasori, after Omoi was able to free Tokuma Hyūga and Ranka from Sasori's control. He could also defend himself against Sasori's puppets at the same time with his swordplay. He can easily counter a barrage of attacks with a single swipe of his blade and just as effectively attack from behind himself surprising his opponent. In the anime, he was shown even able to cross blades against a famous swordswoman like Ameyuri Ringo. He is also shown to be very clever in battle, using feint attacks and deceptions with shadow clones or the Body Replacement Technique as set ups for a final blow.

Nature Transformation
Besides physical combat, Omoi has noted that he can use Lightning Release to a certain extent, such as infuse his sword with lightning. In the anime, he is also shown able to produce a strong bolt that when guided by water will take out a fair number of enemies. He can also collaborate his lightning chakra with others to produce a powerful lightning burst.

Pain's Assault
Team Samui is summoned before the Fourth Raikage, and he and Karui argued over the possible reasons. He thought he was going to be scolded for putting mayonnaise on his potatoes. In actuality, they are to deliver a letter to the Hokage about Killer B's recent capture. Omoi fears he may already be dead, but Karui insists he's being pessimistic. The Raikage tearfully vows that they will rescue B and both Omoi and Karui cry along with him.

Five Kage Summit
As they near Konoha, Omoi worries that, once they got there, a girl would fall for him and, once he had to leave, she would commit suicide out of loneliness. After a short argument with Karui, she threw a rock at him. He then worries that the rock could cause an avalanche that would bury Konoha. Karui insists that he overreacts too much. When they arrive in the village they find that it is nothing but a crater, which Omoi blames Karui for. They ask around and find out that about the recent attack on Konoha.

While Samui meets with the Hokage, Omoi and Karui overhear Naruto, Sakura, and Sai talking about Sasuke, B's captor. They demand all information they have on Sasuke, leading to a brief scuffle between the two groups. Omoi informs them of Sasuke's actions and promises to take vengeance against him which, if Konoha and Kumo are to be allies, they should help them by providing information that can be used to kill Sasuke. Naruto assures them that there may still be time to save B and offers to tell them everything they want to know, which calmed them down. When it comes time do to so, however, Naruto can't bring himself to sell out Sasuke. He offered to let Karui beat him up, which she gladly does. Omoi watches for a time, but then encourages her to stop, commenting that Naruto didn't seem to be the type of guy to betray a friend which Omoi respected, along with his wish to aid them in rescuing B.

After reuniting with Samui, the team goes to the Konoha Archive Library to make a copy of all of Konoha's intel about Sasuke. As they set out to rendezvous with the Raikage, Omoi is glad to see that Karui is worrying about the injuries she gave Naruto. They deliver the information to the Raikage in the Land of Iron before returning to Kumo. When the later Raikage returns to the village with B, Omoi asks him about his new sword.

Fourth Shinobi World War: Confrontation
When the Fourth Shinobi World War begins, Omoi is placed in the Surprise Attack Division under the command of Kankurō. Omoi questions Kankurō's leadership abilities and experience considering they were around the same age, but Kankurō assures him that nothing will stop him from protecting his comrades and completing their mission. When they later set up a base camp, Omoi sets traps around their perimeter. These measures do not stop an Akatsuki attack, yet Omoi is quick to engage the hostile forces. He discovers that they are actually allies, forced to attack them by Sasori. Omoi releases them and, after getting them medical attention, regroups with the rest of his division.

Because Deidara is among the enemy's ranks, the division needs a way to deactivate his earth-based explosive clay. Omoi volunteers to to try neutralising the clay with his lightning-infused sword. After he and Kankurō engage Shin who was being manipulated by Sasori and struggles to hit a moving target, Omoi is finally able to pierce Deidara after they are ruthlessly attacked by enraged Sai and is trapped in one of Kankurō's Kuroari puppets, deactivating his bombs.

Omoi, Sai, and Zaji are sent out to find other Akatsuki cells. They come across and attack a group consisting of Haku, Zabuza, Gari, and Pakura, but Sai's aerial attack of explosive tags fail and Haku attacks them using his Demonic Mirroring Ice Crystals. Before they can be killed the Third Division arrives to help. They later join the division protecting Kakashi while he executed his strategy.

In the anime, he, Zaji, and Sai would later join up with the Third Division and battle Fuguki Suikazan and he and Zaji would go off to aid Maki and her team to fight Gari and Pakura. When Yurui's team was set upon by Ameyuri Ringo, he and a few others were able to escape the attack. As they retreated on Nurui's orders, Omoi was adamant that they could not run forever and needed to make a stand and fight despite Nurui's disapproval. Disregarding his orders, he leaves Nurui and Kayui to confront Ameyuri head on. An intense battle with the kunoichi soon ensued and though Kayui and Nurui returned to offer assistance, they were struck down by the legendary swordswoman and her swords. In the end, Omoi was able to trap Ameyuri in a marsh and as they both sank, reinforcements arrived and were able to rescue Omoi. Ameyuri, who had taken a liking to Omoi, gave him her swords as a parting gift before being completely submerged in the marsh.

Later, when Omoi learned that the Thundercloud Unit, a small new supply unit of children was in danger, Omoi chose to leave his post to save them. Despite some initial refusal from the Raikage, he ultimately allowed Omoi to go with the condition of returning in one hour. Along the way he encountered two thousand more White Zetsu. While a Naruto Uzumaki clone arrived to help him, excited by the idea of becoming Raikage Omoi attacks the White Zetsu Army and accidentally hit Naruto's clone, dispersing it. While Omoi was able to hold his own against the army, they began emerging from a red material and gained its properties starting to exhale a red dust cloud with poisonous effects, forcing Omoi to fight while holding his breath. He found the team and combined their lightning-chakra to disperse the poison cloud. After the Zetsu were defeated and Omoi brought the Thundercloud Unit to their location, Raikage demanded Omoi return to his post before the hour was up or be punished, prompting Omoi to hastily rush back.

Fourth Shinobi World War: Climax
Along with the other remaining members of the Allied Shinobi Forces, Omoi made his way to the battlefield where the jinchūriki were. Meeting up with Karui, the two immediately went to B's side when they arrived, where the two proceeded to make sure that their sensei was all right. They later stood alongside the others to face their opposition.

After B had regained enough chakra and flew towards the Ten-Tails to launch a counter-measure against the Tailed Beast Ball the beast was preparing to launch, Omoi silently mused for his sensei to be careful and later chided him as he flew through the air, that he needed to be more cautious. After receiving chakra from Naruto, Omoi later charged towards the Ten-Tails alongside the other shinobi. Their collaborative effort was enough to separate the two Uchiha from the beast.

Omoi later noticed with shock as the Ten-Tails opened its mouth and started to form an enormous Tailed Beast Ball, wondering whether or not the beast was transforming yet again.

Shikamaru Hiden: A Cloud Drifting in Silent Darkness
Omoi appears in this novel.

Epilogue
Fifteen years after the conclusion of the Fourth Shinobi World War, Omoi accompanied Darui – now the Fifth Raikage – to the Kage Summit in Konohagakure.

Boruto: Naruto the Movie
Omoi makes an appearance in this film.

Naruto the Movie: Blood Prison
Omoi makes a minor appearance when he and his team are talking about the Box of Ultimate Bliss and the Hōzuki Castle with A, and Mabui until he, and the others were knocked out by sleeping gas.

Trivia

 * His name is a pun on two words which have the pronunciation "Omoi":
 * 重い, which means "heavy", contrasting with Karui, which means "light".
 * 思い, which means "thought", alluding to his thoughtful manner.

Quotes

 * (After being summoned by the Raikage) "What the hell does he want? Is it something big…? Or… is he gonna scold us for something? Should I have not put mayonnaise on my fries?"
 * (To Karui) "You need to think things through more carefully…"
 * "No time to be anxious… I won't let you force friends and family hurt one another!"