ttptt, firefly (honkai: star rail), firefly (spring missive) (honkai: star rail), stelle (honkai: star rail), trailblazer (honkai: star rail), honkai: star rail, honkai (series), highres, 2girls, bound, bound wrists, chair, clenched teeth, clothes lift, desk, futa with female, futanari, grey hair, hairband, hand on another's stomach, head back, multiple girls, official alternate costume, on chair, reverse upright straddle, school desk, school uniform, sex from behind, shirt lift, sitting, skirt around thighs, smile, teeth, thighhighs, window