Zen's relationship with Shirayuki began when he stumbled upon her in a forest while he was sneaking away from the castle. Upon seeing her he was distracted and ended up injuring his arm. He begins to question her as to why she is in the forest, and when she asks to heal his wound, he starts to think of her as a suspicious person suggesting the medicine might be poison. Upon hearing this Shirayuki boldly harms her own arm with Zen’s sword and uses the medicine she was going to put on his wound saying, "It's not my hobby to carry poisons around with me”. After hearing this, Zen laughs as his opinion of her completely changes and he gladly accepts the offer of her treating his wound. As time went on and they spent more time with each other he began to fall in love with her. Zen was the first person to convey his feelings as he kissed her unexpectedly while they were talking alone. Embarrassment quickly took over the both of them but when he calmed himself down he told Shirayuki that the next time he touched her he would like to know what she thought. A few days passed and Shirayuki finally made her own feeling clear. Zen then asked her if she would take his hand and her reply was yes. There they began their relationship as lovers; however it is not known to the public yet.