Boruto. Going back to the canon series, while some of these relationships blossomed, providing a deeper insight into the emotional sides of these wonderful characters, others were not fated to receive such happy endings.
While there were many strange relationships in the anime, some were truly heartbreaking as well. As fans had created ships in their own minds, many hoped that the characters in question would end up with each other, eventually. Others, on the other hand, had no chance of being ever united, and remained incomplete stories, as one of the partners was no longer alive - inciting pain, heartache, and even war in the life of the characters.
Sakura And Naruto
Naruto’s feelings for Sakura were not lost on anybody, as the titular character showed his interest in Haruno quite overtly since the first day he met her. However, Sakura was more interested in Sasuke.
The most heartbreaking part about this duo is Naruto’s pitiable attempts to try and woo Sakura, and her nonchalance towards him. Finally, Naruto realized that it was not meant to be, and when Sakura lied about loving him and discarding Sasuke as a common criminal, Naruto couldn’t help but reprimand her for lying to her own self, and denying what she truly feels.
Sakura And Rock Lee
Sakura didn't only break Naruto's heart. Rock Lee, too, fell for the beautiful shinobi. He even swore to protect her till his final breath, a promise he seldom broke.
Despite being impressed by Rock Lee’s make fun of her. Sakura neglecting the feelings of someone who genuinely ed her, instead, pining for Sasuke, someone who never really cared for her and even tried to kill her on several occasions, is something that infuriated and saddened many loyal fans.
Konan And Yahiko
Yahiko’s feelings for Konan were quite obvious, as the former is shown to become jealous and insecure at the prospect of other men dating Konan. Even Nagato teases Yahiko about his feelings for Konan and then reassures him, saying he thinks that she feels similarly as well.
Also, the two lean in while Konan is bandaging an injured Yahiko, indicating mutual affection. However, whether they kiss or not is never shown. Therefore, when Yahiko sacrifices himself to spare Nagato from choosing between Yahiko or Konan, fans cannot help but feel a little gutted to see the irable Yahiko value the life of his love above his own - especially because the sacrifice starts a cycle of pain in both Nagato and Konan’s life.
Karin And Sasuke
Sasuke is shown to be truly cold-hearted during most of the anime, and while his past somewhat justifies his behavior, fans could not help but judge him for the harshness with which he treated his teammate, Karin. While it was confirmed by many, including Suigetsu, Tobi, and Kabuto that Karin was Sasuke’s favorite, his treatment of her seemed to imply otherwise.
Despite the two saving each other on several occasions, Sasuke even stabbed Karin while trying to kill Danzo. However, she is also one of the few people whom Sasuke apologizes to, realizing how devoted she was to him, and that without her, he might not have survived on several occasions. Karin finally stops worshipping Sasuke, realizing the toxicity of their relationship, and eventually adopting a more mature form of friendship. While it is a heartbreaking experience, it is also quite sobering.
Tsunade And Jiraiya
The story of Jiraiya and Tsunade is painful. While Jiraiya loved Tsunade since he first lay his eyes on her, prioritizing Tsunade's happiness over his, she did not let it fester, thinking it would ruin their friendship.
However, after losing her brother Nawaki and lover Dan to the Second Shinobi World War, Tsunade shunned love, fearing she would again suffer loss. Tragically, that was exactly what happened, as the night before Jiraiya left to fight Pain, Tsunade confessed how dear he is to her and that she might give it a chance when he came back. However, Jiraiya didn't return, ironically winning Tsunade her life's first bet of Jiraiya losing, which Jiraiya jokingly asked her to make since she never won any bets.
Kurenai And Asuma
The relationship between Kurenai and Asuma has been hinted at several times in many filler episodes as various characters tease the two about being in a relationship. As both blush, none confirm that it exists. However, as Asuma lies dying, he tells Shikamaru about his child with Kurenai, and asks him to protect his “king.”
The fact that Asuma never got to see his own child, the fruit of his love with Kurenai, and that Mirai Sarutobi grew up without a father, is what makes this even more disheartening. However, as Kakashi and Guy assure Asuma's daughter, there are strong influences of both Kurenai and Asuma in Mirai, making fans shed a tear of happiness.
Izumi And Itachi
Itachi’s entire life is an amalgamation of tragedy, and his love interest Izumi Uchiha is no different. Having saved the young girl during the attack of the Nine-tails, Izumi developed feelings for the prodigious Itachi, who treated her more humanely than her own clan had ever done. However, she was also the first one Itachi killed the night he massacred the entire Uchiha clan.
He killed her first to ensure that he had no lingering doubts about what he was about to do next, but she was also the only other person apart from Sasuke whom Itachi put under the Tsukuyomi before finally killing her. In this tragic moment, Itachi allowed her to live a life full of happiness in the matter of only a few seconds, where the two young shinobis marry each other, have children, and grow old together.
Rin And Kakashi
Itachi is not the only one who killed someone he loved. The burden of that fate also lies with Kakashi, who had to undergo the pain of being the person who killed his close friend and only living teammate - at least to his knowledge - Rin. While Rin had a crush on Kakashi for a long time, the feelings of Kakashi were never made obvious.
But the fact that Rin’s death awakened his Mangekyo is proof enough of how important she was to him. However, unlike Itachi, he did not intentionally kill Rin, as the latter came in front of his Chidori as a means to stop herself from wreaking havoc after being turned into the Three-tail’s Jhinchuriki.
Tsunade And Dan
Death is an obstacle even love cannot conquer, and the story of Dan and Tsunade has a lot to do with death. After her brother Nawaki’s death, Tsunade met the young Dan Kato, who suffered a similar loss in the form of his sister. Being very similar to each other, the two started dating, with Tsunade being inspired by Dan’s zeal to become Hokage and protect the Leaf.
A huge motivating factor to her finally agreeing to become the Fifth Hokage was her brother’s and Dan’s own ambitions of becoming the same. Tragedy separated the loving couple, as Dan suffered grievous injuries while on a mission during the Second Shinobi World War, which even a talented medical ninja like Tsunade could not heal, thereby becoming one of her great regrets in life and making her shun love forevermore.
Rin And Obito
Rin and Obito are perhaps the one couple that every fan of Naruto wholeheartedly rooted for, but one which never found fruition. Instead, Obito waged war against the shinobi world, after being manipulated by Madara and being immensely hurt by witnessing the death of Rin at the hands of his best friend, Kakashi - awakening his Mangekyo in the process.
His love for Rin was profound since childhood, as the latter always ed him and encouraged his dream of becoming Hokage. As he redeemed himself and sacrificed his life to save Naruto’s and Kakashi’s, seeing him reunited with Rin in the afterlife was truly an emotional moment.