Sigma Harmonics

Released in 2008, Sigma Harmonics is a Square Enix RPG for the Nintendo DS, developed by the team that had previously worked on Dirge of Cerberus. It is set in an alternate Tokyo, and focuses on the story of Sigma Kurogami, the future head of the Kurogami clan, a line of 'sound-users' who can create miracles and guard the Great Clock that seals the demonic Ouma. The story begins when someone changes the past, destroying the present day and releasing the Ouma.

To put things right, Sigma and his friend, the card-user Neon Tsukiyumi, travel back the past in order to solve a series of murders in the Kurogami household. By visiting different points in time, finding clues (in the form of 'moments of sound'), and working out the sequence of events and the culprit, the past can be changed, leading to a different murder scenario. In battles with the Ouma, Neon does most of the fighting, using her cards to perform actions whilst Sigma provides the BGM. By playing different tracks, the individual recharge rate for Neon's cards is changed. Neon can also change forms via a form of possession.

This game has an excellent soundtrack, composed by Masashi Hamauzu, and beautiful anime-style artwork. Sadly however, it has not yet been released outside of Japan.

Tropes associated with this game include:

 * Altum Videtur: The theme song is named "Harmonia vita" and has some Latin sprinkled throughout the lyrics.
 * Black Eyes of Crazy:
 * Cool Mask: Worn by the butler.
 * Do It Yourself Theme Tune: Aya Hirano sings the theme song, "Harmonia vita".
 * Evidence Scavenger Hunt: After going back to a certain time and a certain place, Sigma can use his sound-related powers to uncover 'moments of sound' - clues as to what happened in that place during that time.
 * Fight Like a Card Player
 * Flaming Hair: Dickson and Christie.
 * Green Eyes: Sigma
 * Hey Its That Voice: Daisuke Ono is Sigma and Aya Hirano is Neon. Tetsu Inada and Mamiko Noto voice Dickson and Christie. Rikiya Koyama is Shizuma Kurogami. Jun Fukuyama is Rin Yuzuriha. Yu Kobayashi is Yoshiko Kurogami.
 * Humongous Mecha:
 * Impaled With Extreme Prejudice:, at the end of the trailer.
 * Nice Hat: Neon.
 * No Export for You: Bombed in Japan, which sealed its fate in regards to an international release. It doesn't help matters that the game is coded in a way that would make hacking in a fan-made English script impossible.
 * One Winged Angel:  in the final boss battle, This is a Square Enix game so it shouldn't really come as a suprise.
 * Powers Via Possession: Neon uses this to change classes. It also comes with a slight personality shift.
 * Ripple Effect Proof Memory
 * Say My Name: At the end of the trailer when Neon gets skewered.
 * The Summation: After gathering evidence, Sigma can do this via Hyper-Inference (a board with the 'moments' placed on it in the form of medals, which can be placed in different ways, producing different reasonings). Whether he infers right or wrong affects the boss battle afterwards.
 * Time Travel
 * Theme Music Power Up: What piece of music Sigma is playing affects the recharging rate for Neon's cards.