This page outlines Yumi's relationship with characters in the Senran Kagura series.
Yumi has the utmost respect and love for Kurokage as he was the one who gave her purpose in life after the death of her parents.
While Yumi's initial intention for becoming a shinobi was to seek revenge on those who killed her parents, she eventually changed her mind and wanted to use her power towards creating Kurokage's ideal world; a place where no evil exists.
Little did she know that the path she was walking was the opposite of what Kurokage had intended for her. He never wanted her to follow in his footsteps and didn't want her to feel like owed it to him to carry out his dream.
During the Shinobi Battle Royal in Shinovi Versus, Yumi experienced inner conflict on her feelings regarding good and evil. As she battled against the other schools, she began to question if good and evil were as black and white as she had always thought. However, she was reluctant to think otherwise as she believed it would go against Kurokage's teachings despite her newly developing feelings on the matter.
By the end of the Shinobi Battle Royale, Yumi accepts that the concept of good and evil wasn't as simple as she had originally thought, and hopes that Kurokage can forgive her for going against his teachings. However, she doesn't know that Kurokage is happy for her and the path she chose.
Yumi's Mother & Father
While very little is known of Yumi's parents, it's implied that she had a very good relationship with them considering the fact she wanted to claim revenge for the deaths during the start of her shinobi training.
Gessen Girls' Academy
Murakumo and Yumi seem to have a stable relationship. It is clear Yumi does not think ill of Murakumo in any way and merely wants her to be more confident in herself. This is demonstrated in Murakumo's Shinobi Girl's Heart story where Yumi even goes as far as trying to flatter Murakumo about how she doesn't need her mask.
Yumi seems to have the best relationship with Yozakura out all the Gessen shinobi. Yozakura has a great respect for Yumi and is the only member of Gessen that is as diligent as she is when it comes to their training as shinobi.
Due to their similar work ethics, Yumi and Yozakura spend the most time together and often have one-to-one sparring sessions. When the others are goofing off, Yumi feels as though she can always look to Yozakura for support and agreement on the situation.
Yumi thinks highly of Yozakura's skills and power, viewing Yozakura to be stronger than herself despite Yozakura believing Yumi to be the stronger of the two since Yumi is the leader and always wins their sparring matches.
In Estival Versus, Yumi decides to try and be more lenient and considerate of her comrades. This leads to Yozakura taking on the disciplinary role herself, scolding the others when they're not listening to Yumi so she won't have to do it herself anymore.
Yumi and Shiki have a stable relationship. Shiki seems to really enjoy coming to Yumi and asking her questions to which Yumi will always go above and beyond to get an answer to. Shiki thinks very highly of Yumi and doesn't think ill of her harshness as she knows that Yumi is only hard on them all because she cares deeply about them.
While Yumi is seen interacting with Minori the least of the girls in Gessen, it is implied that they two of them share a generally stable relationship as demonstrated with Minori addressed Yumi as Gessen's "Big Sis" during the Hanzo arc of Shinovi Versus.
Hanzo National Academy
In Gessen's Story Mode, due to contrasting beliefs, Yumi and Asuka were immediately at odds with one of another in their first battle. Yumi believed in wiping out all Evil Shinobi while Asuka believed that there's more to Evil Shinobi then just being evil. Yumi refused to accept such beliefs, resulting in them clashing. Upon learning about the different forms of Evil Shinobi, Yumi has a change of heart and settles her differences with Asuka and the two became friends after their final battle.
Hebijo Clandestine Girls' Academy
In Hebijo's story of Shinovi's versus, Yumi believes she and Miyabi are similar, due to older adult figures influencing their Shinobi paths and their devotion to them. The two seem to have at the very least a mutual respect for each other.
Despite Yumi's clear and desperate desire for her to stay away, Ryōna continues to pursue her while finding joy in the fact that Yumi is relentlessly giving her the cold shoulder. In the end Ryōna believes Yumi is just playing hard-to-get and decides to admire Yumi from the distance, wanting to dance with her even though she can't and that makes her extremely happy.
Homura's Crimson Squad
Yumi's relationship with Homura is roughly the same as it is with Miyabi. The two seem to have a general respect for each other and no real signs of animosity. They are perfectly capable of having a normal conversation and as shown in the Crimson Squad arc of Shinovi Versus, Yumi acknowledges the hardships of being renegade and looks forward to seeing where Homura goes on her Path of the Shinobi.