Ena first thought of having a relationship with Godou as simply an assignment, a marriage of convenience nothing more. However, after his battle against Ame no Murakumo no Tsurugi and saving her from its wild control despite attempting to kill Erica, she has seemingly fallen in love with him. She has no problems showing herself in the nude to him and performs varies act for him. Despite wanting to be near Godou, Ena does not mind being his mistress as she is happy to be by his side. Ena stated that the reason she loves Godou so much because he is very powerful, dashing, and very compatible with her. By the end of series, their relationship have gotten so intimate that they have sex after Godou returned from his parallel worlds travel.
The pair are childhood friends, though they have very different personalities. Ena is always trying to push Yuri to live a little and be more relaxed and modern in how she acts. Out of all the four main girls, Ena is the closest to Yuri and showed signs to be more willing to perform service to Godou with her more than anyone else. However, she does enjoy teasing Yuri, striping her twice in front of Godou (one of them being a future dream) but does show to care for her as she was okay for Yuri to be the main wife while Ena be the side wife. However, by the end of the series, the two became comfortable enough with one another that both of them were willing to have sex with Godou at the same time.
The two have something of a rivalry because of Ena's near defeat of her while in the Netherworld, and because of her romantic interest in Godou. Erica considers her to be the toughest rival in the group because of her innocent and unpredictable nature that even Erica has a hard time guessing. By Volume 14, however, that the two are more comfortable around each other more and were willing to let the other one get Godou attention if he desires to and would not complaint. Even Erica had shown signs of teaching Ena ways to seduce Godou.
Appears to have a close relationship to the former Heretic God, as she wields his sword Ame no Murakumo no Tsurugi, and calls him Grampsy.