Chapter 5 of Hell's Paradise: Jigokuraku.
As Gabimaru fights Sagiri, he remembers the Iwagakure Chief's words as an infant about how sentimentality is weakness and how if he is not strong he won't be capable of protecting anyone. After what Kisho said about Iwagakure getting involve in the mission, Gabimaru knew that it would all be over for him in terms of finding the Elixir of Life and had no choice but to kill Sagiri. As they fought, Sagiri and Gabimaru were holding back in confusion. Gabimaru then remembers his wife's words on how sentimentality is not a form of weakness but a form strength as a warrior but how it also taught him hatred. He then goes back to remembering the chief's believes again and cuts Sagiri's sword in half. Gabimaru then proceeds to attack, telling her that resisting is useless and that he apologizes. However, Sagiri provokes him by saying that he wasn't capable of feeling sentiment given his reputation. Gabimaru agrees to her statement and pins her down in a murderous state. Before he could kill Sagiri, he is once again reminded of his wife's influence and stops himself from killing her. Because he couldn't bring himself to kill Sagiri, Gabimaru sheds tears as he believes that with the way he is he won't be able to survive on the island or see his wife. Sagiri tells Gabimaru the fact that he can feel emotions is a sign of strength and not weakness and promises him that if he faces his emotions while reclaiming his life then she will support him throughout the journey. Finally, Sagiri tells Gabimaru that he is no longer the man he was before and sheathes his sword.