A year has passed after the events of true ending of Melty Blood, with the death of Night of Wallachia in the hands of Sion Eltnam Atlasia, Arcueid Brunestud and Shiki Tohno and also after the events caused by White Len and Aoko Aozaki in Melty Blood Re-ACT and some smaller events in Melty Blood Act Cadenza (Miyako Arima, White Len, Neco-Arc and Neco-Arc Chaos). The combatants who were involved in the case of the two previous TATARIs in Misaki Town feel that something is missing, as if they had forgotten of someone who they knew some time ago (Sion Eltnam Atlasia) and that the events caused by the Night of Wallachia in Misaki Town one year ago returned, as if it had never happened before.
This makes the combatants as Shiki, Sion, Arcueid, Ciel, Akiha Tohno, Hisui and Kohaku act and remake their roles in the event known as "Hologram Summer", caused by the Dead Apostle Ancestror, Night of Wallachia once again, and beyond of enemies that appeared and was materialized by TATARI original caused in Misaki Town a year ago, also appear three new combatants who were not present in the original event, which are the friend that Sion lost four years ago, Riesbyfe Stridberg, the greatest personal enemy of Shiki Tohno/Shiki Nanaya who murdered the entire clan of Nanaya, Kouma Kishima, and the responsible for the vampiric attacks caused more than two years ago in Tsukihime, Michael Roa Valdamjong (Near-side version).
But as with Sion had already perceived, and also those not directly involved with the events of the first Melty Blood (Miyako Arima, White Len, Aoko Aozaki, Neco-Arc, Neco-Arc Chaos, Mech-Hisui and his copies and all the manifestations generated by TATARI in the past (Red Arcueid, Shiki Nanaya and Nrvnqsr Chaos), except Night of Wallachia who also had their memories altered a bit, noted that there is a new entity in the shadows, hidden from everyone and everything and is this entity, that somehow, reactivated the TATARI phenomenon that should no longer occur in the world again with the death of Wallachia in Melty Blood and the defeat of White Len in Melty Blood Re-ACT in the past. This new enemy is willing to redo the events caused in first Melty Blood with a sinister goal of eliminating all life on planet earth and exterminate all humanity for using TATARI, by sealing the reality inside of the fantasy by using a forbidden ritual that can transform everything and everyone in Philosopher's stones, with the objective to build a super computer that would become an eternal record of the existence of the human race, to cause their own version of the end of times'.
While Sion and the other individuals who were not affected by changes of altering memories, days and dates of this new entity, trying to solve the new case of TATARI and do Shiki and the others returned to remembering of Sion and that the TATARI already caused by Wallachia occurred a year ago, the other beings materialized by TATARI resolve to follow their 'scripts' and take the opportunity not only to cause terror in the inhabitants of Misaki Town, but want to take revenge on those responsibles who caused their 'deaths' in the past in this city, with some they solve try break free from the control this new TATARI to go behind of the responsible for the remake of Hologram Summer and try to prevent that this entity destroy all life on earth and all humanity.