Yomei Ikkagetsu Kazoku no Fukushuu

The Naito family is suddenly diagnosed with an incurable disease and told they only have one month left to live. When asked if there is anything they want to accomplish before they die, the youngest brother, Tomoya, answers, "revenge." This is the story of a broken family as they try to reconnect before their final moments.

(Source: Square Enix, translated)