The Diary of a Teenage Girl wants you to be uncomfortable. It demands you be a least a little unsettled by its core focus, centered on a sexual relationship a 15-year-old San Francisco artist develops with her mother’s 35-year-old boyfriend in 1976. It’s unwavering and bold, and rightfully so. The progressive coming-of-age dramedy needs to be uncompromising to puncture through its cluttered genre, and thankfully it succeeds. And then some, in fact.

In adapting the semi-autobiographical graphic novel of the same name by Phoebe Gloeckner, screenwriter/director Marielle Heller’s tempestuous but deeply felt debut incorporates the youth-centered exuberance of Gregg Araki, Todd Solondz and Jamie Babbit with twinges of Ralph Bakshi and Terry Zwigoff, inviting us into the pulpy surrealism of our lead Minnie’s (Bel Powley) artistic point-of-view. It’s a vividly detailed and beautifully realized look into maturity, touching upon wonted themes in the formula but approaching them with a veracious empathy. Even when its narrative structure is a tad too rudimentary, the journey feels authentic, eloquent and striking enough to get absorbed, and it's well-made and astounding intimate enough to want to get sucked in.

Coming-of-age dramedies often try presenting one’s sexual awakening without any genuine sincerity. Not so with Heller’s movie, however. From the minute it starts, and you hear Powley say, “I had sex today. Holy s**t” — conglomerated with its bleeding heart plastered on the screen and an affectionate gaze for the time period — the spirit is felt. Like some other teen sex fables, The Diary of a Teenage Girl is abrasive in its convictions to stand against the tide and shock its audience. But it earns its surprise factor, especially as it continues. The somber, reflective and reformist mentality in constant acceleration here carries a proudly pronounced vision of youthful up-bring and personality developing. Though it can echo its inspirations, like American Splendor or Crumb, for instance, its colorful and confident demeanor gives its occasionally borrowed style a mandatory stagger.

The visuals are as rich as the context, and Heller not only knows it but celebrates her spunky attitude, much like her main character. It’s a fearlessness equaled by her star. The highly expressive, wide blue-eyed 23-year-old actress dedicates herself completely and wholly to letting Minnie come alive. The character’s insecurities, vulnerabilities and ultimately acceptance of herself are played out lovingly and touchingly, as Powley’s never afraid to liberate herself — physically or emotionally — to let the adaptability of the character become realized at every step. It’s a performance shining tremendously bright and promising an astounding career to come, and it’s one only rarely overtaken by her more experienced co-stars — namely Kristen Wiig, as her coke-sniffling, chain-smoking, single-mom Charlotte, and Alexander Skarsgård, as their mustache-sporting, beer-guzzling shared love Monroe.

Wiig, in particular, is exceptionally commendable here, continuing her winning streak within maturely themed recent dramas and presenting herself in a role almost entirely alienated from any she’s played before. It’s one she downright dominates, proving once-and-for-all her durability may be more pertinent in the dramatic arts than in the funny business. And while the drama here can be quite hefty, particularly near the end, don’t let this underscore just how peculiarly funny Heller’s movie can be. The blend of illustrated animation and Heller’s keen eye for visuals presents a distinctly humorous reflection of Minnie’s events, all while letting them add to her depth and not distract from her central progression. Her love affairs and romance with Monroe is glossy but doesn’t glamorize their actions. It presents the reality of their relationship, while also adopting Minnie’s blinded presumptions of what’s happening in her life. It’s a starkly thin tightrope to cross that’s remarkably self-reliant and gently crafted by its first-time filmmaker.

Brave, vulnerable and emotionally honest, but warmly heartfelt at its core, The Diary of a Teenage Girl is another distinct and impacting YA tale in an exceptional summer for the genre, one also populated by Me & Earl & the Dying Girl and Dope. Heller's compassionately woven and humbly felt debut is the kind of personal tale you don't mind getting uneasy to explore, as long as when it's as compassionate and heartfelt as this. It's less about reinventing itself as much as it's about honing in something unshakable and, though it doesn't necessarily say anything new, it's gracefully-told depiction of adult fertility is an open-book worth reading.