Most massive stars live in close binary systems that will interact during their lifetime. As a result of these interactions, massive stars can lose their outer layers, gain new layers, or merge. This can greatly affect their interior structure, late evolution, death, and the nature of the stellar remnants they produce. In this thesis, we investigate the late evolution, deaths, and afterlives of massive stars that transfer their outer layers to a binary companion. To this end, we performed and analyzed stellar evolution simulations. We show that stars that experience stripping by a companion can retain some of their hydrogen-rich envelopes, especially at low metallicity. Those that do, can expand to giant sizes at late stages of their evolution and are likely to interact again with a companion. Further, we show that binary stripping not only affects the outer layers, but also the deep interiors of our massive star models, and that this has interesting consequences for their explodability and nucleosynthesis. In addition, we present TULIPS, a visualization tool that was developed and applied to the research that is part of this thesis. This tool enables novel visualizations of the structure and evolution of stars. Finally, we give an outlook on future avenues that have the potential to constrain the properties of binary-stripped stars.