She doesn't love him or was loyal to him; she's just a bioweapon slutting her way to gather intelligence and complete her duty. Then she dumped and left him with her clones - walking away happily & fully clothed with gathered data. As a Yandere connoisseur, she doesn't seem like one to me.
It's also interesting how this is an original work. The artist's Pixiv tagged it as so: https://www.pixiv.net/en/artworks/79779286 Thought it was a parody work, since it feels like their relationship was already established within a bigger plot that wasn't present in this doujinshi. Plus all this bioweapon of neighboring country and spy stuff; would be an interesting plot.
Base +7, EllincedeT +10, Venoman +6, RandomDudeH +5, bahki +6