This study aimed to elucidate the experiences of Japanese persons with hematological malignancy (PHMs) in communicating with health care professionals (HCPs), from diagnosis to the end of life, as recalled by their families. We interviewed 14 bereaved families and analyzed the data using the basic techniques of grounded theory. We found that PHMs lived to the fullest possible when they experienced ownership of their illness process despite their disease. The ownership was made possible by active communication from HCPs: first, acknowledging the PHM’s way of life, including reaching out from the HCPs and appreciating sincerely PHMs’ hopes and will; and second, paving the way ahead, including giving prospects and offering choices. The study underlines that rather than just providing information about the disease, HCPs need to actively ask about and show respect for the PHM’s way of life. Only after achieving this can HCPs communicate possible future pathways with PHMs.