This is a perfect combo of my two favorite ideas for that space under the stairs leading to the basement. A reading nook AND book storage and shelves . assuming that there is enough space for this there.
How to build a romantic seat for two: Build your own retro dining nook for a cosy corner. Sure you could cuddle on the lounge with a box of chocolates, but to get really intimate, how about enjoying breakfast, or a lovely meal and a glass of wine, in this