In the second game, Nobunaga spends his entire story trying to unite Japan by slaying everyone in his way. But then during the infamous Honnouji attack, he manages to slay Mitsuhide and eventually after shedding a single tear for him, Nobunaga carries the former warrior's body out of Honnouji in his ending. His Dream scenario, Nobunaga's Dream: Nobunaga Unites Japan has him honoring Mitsuhide's memory, by issuing an order to his troops to not slay a single man, but instead have them retreat or surrender. The mission ends with him remembering of Mitsuhide.
In the third game, Nene spends spends Hanzo's entire story route badgering him to learn the flute, so he'll have something he can do when the conflict ends, a notion he constantly rebuffs. His ending has him playing the flute while surrounded by the dead and dying of the final battle, which Nene thanks him for in her dying breaths. The last shot is Hanzo entertaining some children with his music.
Third game, Nobunaga's ending. Mitsuhide is defeated, but does not die. Nobunaga lectures him a bit about how it is impossible to have everything and how things are changing as they speak, and to end it all... Nobunaga forgives him, both vanishing in a sea of flames, but hopefully to become living legends.
Remember the tearjerking and Downer Ending for Oichi's story in the second game? Thankfully, KOEI has been kind for her in the third game. Even after Nagamasa sent her back to the Oda to ensure her safety like he did in the previous game, Oichi still wants and eventually managed to return to her husband, saying that she choose to be with him. Awww, they're not a Sickeningly Sweethearts for nothing, are they?
Hanbei's death scene has him declare that he will always be a light watching over Kanbei.
Samurai Warriors 4
In the fourth game's Chronicle Mode, one event with Hideyoshi sees the player tasked with finding someone from Hideyoshi's childhood who used to bully him, so Hideyoshi could get some payback. When the player finds the scoundrel in question, he finds him all grown up, dirt poor, and hungry. If the player chooses to fib and tell Hideyoshi he wasn't home, Hideyoshi will write a threatening letter for the player to deliver to his house...except it's not a threatening letter, but a notice stating the former bully was now tax-exempt. What a stand-up guy, that Hideyoshi.
One part this, one part Bittersweet Ending; after completing the gaiden stage for Legend of Kyushu, Yoshihiro is visited by Takatora who gives him Toyohisa's helmet. He's also relayed the news that Ieyasu has allowed his clan to keep the lands that were always theirs; all in part due to everyone recognizing the Shimazu's and more importantly, Toyohisa's valor. The boy's Heroic Sacrifice not only saved him, but managed to save his clan's home at the same time...
Kotaro is selectable in the Sanada Legend version of the Osaka Campaign's Toyotomi Side, if used he can encounter Lady Hayakawa. Upon beating her, he then let's her go with a very important line. Coming from anyone else, the line he says wouldn't be anything special - but the fact that it comes from him shows how far his character has come. The very rare sound of honest solemnness coming from Kotaro is what makes it:
Kotaro: ...It is too early for you to join Ujiyasu just yet...
Pretty much all of the Redux versions of the final battle scenarios in the Sengoku Musou Chronicles 3, which all lead to great heartwarming endings in their own right.
The ending in Koshosho's expanded storyline in 4-II. After she rescued Gracia, both ladies hug each other. The ladies then vow to live long lives for the loved ones whom died before them. Really, it's too adorable and heartwarming to see!
The Furo Scene (yes, you read it right) in the opening scene of Gracia's expanded storyline for 4-II. Sure, it's pure fanservice, but it's cute at the same time to see Gracia and Koshosho teasing Naotora.
In 4-II it's possible to team Naotora and Naomasa up as early as Naomasa's first Story battle. They tease each other as mother and son as much as they praise each other for their skills.
Samurai Warriors Chronicles
In the first game, one of the gaiden missions involves Gracia trying to find someone to marry in order to avoid an Arranged Marriage. Not only does it turn out that the groom is not who she thought it was, said groom is a Victorious Childhood Friend who not only loves and respects her, but ensures her survival by hiding her when Mitsuhide's family is executed after he betrays Nobunaga, losing his own life in the process.