Originally thought to be two distinct Diary users, Marco and Ai are, in reality, the same Seventh Diary user. Upon their introduction, Marco and Ai utilized apprentice diaries that Yuki and his allies mistook for their genuine Future Diaries. Marco's Unbeatable Brawler Diary forecasted attacks before they occurred, while Ai's Flirting Diary pinpointed any man she wished to flirt with in the future. Their actual diaries are the Exchange Diaries, which predict each other's immediate futures. The duo demonstrates remarkable teamwork, leveraging their diaries to compensate for each other's vulnerabilities.
Marco and Ai, both orphans, fell in love after Ai was adopted by Kamado Ueshita, who also serves as Marco's guardian. Their bond is so profound that they aim to win the game to become God and live together eternally. Interestingly, Marco and Ai's names are inspired by the Roman gods Mars and Venus, respectively.










