Raising Heart, an Intelligent Device from an unnamed ancient civilization, was unearthed by archaeologist Yuuno Scrya in its dormant state—a crimson spherical crystal. Recognizing Nanoha Takamachi’s latent compatibility, Yuuno transferred the device to her, awakening its AI. Addressing its wielder as “master,” it specializes in long-range bombardment magic, providing tactical analysis, spell calibration, and precision targeting. Its name derives from a heart-shaped core in its original design, though this was superseded by the red sphere during activation.

Severely damaged by Vita’s Graf Eisen, the device was reforged as Raising Heart Exelion, integrating a Belkan cartridge system that boosted firepower via rifle-style magazine loading. Later enhancements introduced an Accelerate Charge System, enabling propulsion bursts and Strike Flame maneuvers. Its forms diversified across timelines: the primary continuity featured Axel Mode for aerial mobility, Buster Mode for amplified bombardment, and Exelion Mode for maximum-output strikes. Movie adaptations replaced the original Shooting Mode with Canon Mode, incorporating a rotating trigger mechanism, and Bustercanon Mode for combined assault-sealing operations.

Subsequent upgrades expanded its versatility. Standalone Flight Mode permitted autonomous hovering, freeing Nanoha to wield dual armaments. In cinematic iterations, it synchronized with Barrier Jacket Fortress Mode to manage armor systems and emergency shields, later fused with nanomachines and a Variant Core to establish Formula Mode for adaptive combat. Alternate universes, such as Brave Duel, reimagined it as a sentient combat avatar.

Though its origins and pre-Yuuno history remain undocumented, the device’s AI fully awakened only through Nanoha’s synchronization. Across multiverse iterations and technological evolutions, Raising Heart persisted as Nanoha’s steadfast tactical companion, continuously refining its functions while retaining its core identity as her primary weapon.