[Yoshida Tobio] Together with Onee-chan (COMIC Ero-Tama 2015-07 Vol. 9) [KenGotTheLexGs]

When their mother rushes off to care for their injured father, a curvy older sister is left in charge of bathing her shy little brother Haruito—a chore she turns into a very thorough anatomy lesson. Between scrubbing him down under the shower and explaining 'pistils and stamens' on her bed, her patient sex-ed escalates into hands-on demonstrations neither of them expected. Blushing, curious, and increasingly bold, the young boy learns exactly where 'the thick stuff' is supposed to go in this playful sibling romp.