REVIEW: ‘Glass Heart’ Offers Messy, Musical Catharsis

The best, brightest moments of the Netflix series Glass Heart are the musical ones. Perfecting the bottled brilliance of how music connects us, the series excels in its earnest belief that the right note, played at the right time, can change our lives and alter how we perceive the world—and who we share it with. In these exuberant, emotionally explosive moments where the cast takes the stage as the band TENBLANK, Glass Heart triumphs. 

It was only natural for the sweeping, musical moments to stand out. Some of Japan’s most prominent artists contributed songs to the making of the series, such as Radwimps vocalist Yojiro Noda, Taka from ONE OK ROCK, Zarame, Yoohei Kawakami of [Alexandros], and more.

Drawing on influences from some of the biggest names in J-Rock and J-Pop today, Glass Heart soars to its highest peaks in these moments of anthemic bliss, wearing its heart on its sleeve through catchy melodies and committed performers. The four actors who comprise the fictional band put in over a year of learning to play their instruments, and it pays off. 

Where Glass Heart falters, however, is in pieces of the story itself. Unruly yet ambitious, the series tries to tackle too many storylines and takes the least interesting route in one of the most vital threads. The charm is there, and most of the actors can carry the more lackluster sequences, which suffer even more when its clear the heights the series can reach. But there’s a very unfortunate issue keeping it from reaching its greatest potential: the main protagonist, Akane Saijo (Yu Miyazaki).

Akane is too polished to make for an interesting protagonist.  

In a thunderous opening, Akane is unexpectedly ousted from her previous band moments before a performance. In an act of defiance, she performs in the rain to a gathering audience as the festival goes on in the background, crafting the perfect duet for her and the reclusive yet brilliant musician Naoki Fujitani (Takeru Satoh). This moment binds them, leading Naoki to later choose her to join his new band, TENBLANK. 

Naoki is determined to see his new band find stratospheric success. Along with guitarist Sho Takaoka (Keita Machida) and pianist Kazushi Sakamoto (Jun Shison), the four establish their sound as they work out creative differences. The band soon finds fame while battling Naoki’s many secrets, outside threats, and the struggles that stem from the severe shift from obscurity to stardom. 

It’s desperately unfortunate that the weakest link in the series is the key point of the narrative, around which the other main character orbits. Because there’s a lot of the series that’s engaging and transportive. There’s a version of Akane that’s interesting. There are pieces of it when she’s performing. It’s not a dismissal to say that Yu Miyazaki is at her best when she’s drumming. But she’s the most alive in these moments. She’s free, unburdened, and less affected in her delivery. 

Keita Machida once again demonstrates his magnetism. 

Drummer Akane is the most interesting because she isn’t forced into a strict, limiting box of female heroine. She’s too neat—an idealized fan insert of what it would mean if you could share a room with your favorite musician and inspire him through your sheer curiosity and talent. The writing sands down any rough edges—any hint of them—in favor of a character who is merely 2D and reactionary. 

The characters surrounding her are much more interesting, even if Takeru Satoh overtly indulges in a seemingly favored posture. He leans, a lot, embodying a live-action anime character (fitting for the actor) with so, so many head tilts, and Cheshire cat grins. Satoh has clearly dreamt of playing the role of rock star and comes to it with feverish gusto, which works for the most part, even if it tends to veer into caricature. However, that over-the-top nature is also due to the covetable wardrobe and the array of billowing jackets that costuming sticks him in. 

The most interesting characters are in the support roles. Keita Machida once again demonstrates his considerable and effortless charisma as the guitarist, Sho. Spending the majority of the series as a character taking in the drama that unfolds in front of him, he gets his moment in the sun towards the end of the series as his true feelings overflow. Machida and Satoh have fantastic chemistry together, equal parts playful and intense, and offer some of the best on-screen sparks, even if that isn’t the series’ intent.

It’s also often where Satoh’s Naoki is the most animated while off stage. Playful and biting rather than perpetually enigmatic. Naoki feels the most real and tethered in the back and forth between him and Sho and another, fellow rock star, Toya. 

The Netflix series offers cathartic escapism despite contrasting tones. 

It’s just another example of how Glass Heart struggles when it aims for the most predictable narratives. The romance is, without question, the least engaging aspect. There’s no tangible passion to it, and it screams artificial. So much of Glass Heart is about the pure, cathartic escapism; yet, specific character dynamics and relationships seem hell-bent on withholding that distinctive spark. 

Sho and Kazushi both deserved more time for their characters to develop. There’s a reservedness to both Machida and Jun Shison’s performances that’s refreshing in contrast to the broad strokes Miyazaki and, to an extent, Satoh employ.

The entire cast is a mix of competing acting styles. Masaki Suda, as another popular singer, Toya, goes so big that it pushes the series’ limits. That said, Toya also has one of the best performances in the series. He has a relationship with a fellow band member that is teased but underdeveloped. Akari Takaishi, of Baby Assassins fame, also lays it on thick as a pop singer embroiled in her own controversies, due to her manager, played by Naohito Fujiki but delivers similarly fun and enthusiastic musical performances.  

The live performances come alive through the massive scale and production. 

It makes Erika Karata’s subtle performance as TENBLANK’s manager more noteworthy. The effect of these differing tones is a bit clashing but the strengths manage to persevere due to the charm of the strongest characters.

The actors’ ability to play their own instruments is fundamental to the success of Glass Heart because it allows the director to pull out and weave throughout the live performances. Directed by Kohtaro Goto, there’s a reason why the concert moments hit all the right chords. These are the moments where over-the-top makes sense. There’s no over-reliance on clever editing tricks to hide what the actors can’t do.

As a result, the scale of the live performances expands until they become all-encompassing. They beautifully execute the feeling of being able to feel the reverberations of the bass and see the singers sweat up close. Sharing space with others who love what you love. 

Based on the novel of the same name by Mio Wakagi, Glass Heart takes some shortcuts in pushing TENBLANK to super stardom. In one episode, they’re shooting their first music video, and in the next, they’re selling out arena venues. Certain storylines with adversaries are tied up too neatly; although, credit to the series for ending on a somewhat ambiguous note that still offers the right amount of closure. 

Glass Heart hits all the right notes when TENBLANK performs.

Glass Heart works when it reaches for the stars and goes big, bombastic, and loud. The tremendous work of the musicians involved, along with composer Masakatsu Takagi, lends the series a potent, emotional pull, featuring catchy hooks and twinkling notes that create a magical atmosphere.

The series is an amalgamation of parts, and the relationship drama suffers due to misguided writing and a romance devoid of any heat. But goodness, when Satoh begins to belt, and the band comes together, they captivate and whisk us away, leading us to the next episode button before we’ve even realized it. Music and its healing properties are the beating heart of the story, creating a final product that is both mesmerizing and frustrating. 

There’s no doubting its quality regardless of its faults. Glass Heart succeeds due to its contagious, undeniable energy. The series struggles with the predictable and fundamental steps of romance drama tropes. However, it gathers its strength through its formidable music, epic scale, and the brief moments where the series reminds us that a mutual love of art, an unwavering need to create and share our creations with others, is the most potent type of unifier. 

Glass Heart premieres July 31 on Netflix.