"hayaku kudasai, Reimu ni ippai ... no osaisen." The no particle binds a word to what comes after it, so the whole sentence is (Hayaku kudasai) (Reimu ni) (ippai no osaisen), (Give quickly) (to Reimu) (a lot of offerings). But when you cut off the no osaisen, ippai wants to stick to Reimu, (Hayaku kudasai) (Reimu ni ippai). Ippai also takes on its other meaning of "full," as in a spoonful, or a plateful... or a Reimu-ful. (Give quickly) (A Reimu-ful). "Please hurry, fill Reimu up!" NONE of this touches the fact that this is an acrostic, HAyaku KUdasai REimu-ni Ippai -> HAKUREI, so you would naturally expect the sentence to end with the ippai, since the acrostic is done at that point. So, I don't know. "Reimu wants a full load ... of offerings"? Innuendo takes some creativity.
