In SB2, when Masamune encourages Itsuki not to give up on her dream. It was so sweet seeing how kind and understanding he was to her.
Itsuki: You're the same! You think of us as filthy worms!
Masamune: Ha! I don't know who spouted such nonsense, but bring him here, and I'll give him a good beating for you.
In the manga Sengoku Basara 3, Masamune shows Itsuki his men helping to build the village that was destroyed, helping her realize that they both want a peaceful world. And later, Masamune gives Kojuro a rice ball Itsuki had made.
Masamune: "I can't let the hands that make such delicious rice be tainted with blood, I guess."
Also in 3, Ieyasu decides to take Oichi in when he realises she lost her memories, promising to protect her and help her search for happiness.
Likewise, when Yoshitsugu uses the last of his life force to restore Mitsunari's health at the Sekigahara Infiltration.
Plus when Ujimasa gives Yukimara medicine that'll help cure Shingen. Chances are Yukimura won't be the only one crying Tears of Joy.
Toshiie and Matsu's reunion after she is rescued from her kidnappers, complete with Keiji and Magoichi smiling awkwardly.
Mitsunari trying to kill Motonari on Motonari's blue path after learning he plans on killing Motochika. Even Yoshitsugu seeks Motonari's head for betraying Mitsunari! Sadly they both end up dying in the end against him.
From the anime Season 2, Keiji's speech to Masamune, after the latter asks him why he never draws his sword. It just goes to prove that he's got the biggest heart of anyone, even if being a pacifist means he's doomed to keep losing.
If the only time you meet people halfway is when you're stabbing them, this war's never gonna end. It's strange, I know, but just the tiniest things in common are enough to make you not want to hurt a man. People are good, basically... I need to believe that.
The manga Sengoku Basara 3 has Masamune, badly injured and barely able to stand, attempting to stop Mitsunari from killing his men. Becomes a Tear Jerker when he fails and Mitsunari slaughters most of them.
Masamune: Sorry, but I can't die in a place like this. I will protect these guys. I won't let a single thing be taken from me. I will create a world in which everyone can live with a smile.