In 1983, the Yi family, led by the determined father Jacob, embarks on a new journey as they relocate from California to a remote plot of land in rural Arkansas. Jacob dreams of cultivating Korean produce to sell in Dallas, but their new home—a sizable trailer—fails to impress his wife, Monica. Despite her protests and dissatisfaction, Jacob makes a bold choice, opting out of hiring a water diviner who offers to help them drill a well, instead digging one himself.
In this transition, Jacob receives support from Paul, a quirky local resident and Korean War veteran, who lends a helping hand. While Jacob is filled with hope for their new life, Monica grapples with her feelings of disappointment and concern for their son David, who has a heart condition that limits his activities. Their constant bickering over their isolated living conditions is overheard by David and his sister Anne, deepening the tensions in their family life.
Monica yearns for proximity to essential amenities, such as hospitals and schools, while Jacob's ambitions drive him to invest in a tractor, further aggravating Monica’s frustrations. To assist with childcare, Monica's mother Soon-Ja is brought over from South Korea, bringing with her cherished gifts and cultural items. However, Soon-Ja's adjustment to American life is not seamless; she struggles to connect with David, who feels out of place and rejects her traditional caregiving methods, such as administering the medicinal tonics she brought.
As Jacob makes strides in his farming endeavors, he faces a series of setbacks, including a well running dry and deal cancellations by vendors, piling on the pressure. Monica’s financial anxieties reach a boiling point as she questions the viability of their new life, setting the stage for a fragile marriage. Despite Monica's various pleas to return to California, Jacob, fueled by pride about their cramped former home and his commitment to sending remittances back to Korea, remains steadfast in his desire to succeed.
A turning point occurs when Soon-Ja takes David to plant Minari seeds near a creek, sharing valuable wisdom about this resilient plant. Her intention to bond with him begins to break down his earlier resentment. However, tragedy strikes when Soon-Ja suffers a stroke, leaving her with limited mobility and speech.
Their journey culminates in a trip to Oklahoma City for David's heart check-up and to meet a potential vendor. While they celebrate good news about David's health and a new deal for Jacob’s vegetables, an emotional confrontation reveals the cracks in Jacob’s priorities, raising doubts about their family unity. This tension culminates in a disastrous fire at the barn caused by Soon-Ja's moment of distraction. As chaos ensues, Jacob and Monica rush to each other’s aid, ultimately realizing that their love for one another outweighs their previous grievances.
In a poignant moment, we witness Soon-Ja's children guide her back home, establishing a fragile connection before an exhausted family falls asleep together. A short time later, the family consults the water diviner, finally finding a spot for a second well, indicating their determination to remain rooted in their challenging yet promising new life. Jacob and David venture to harvest the flourishing Minari, reflecting on the wisdom instilled by Soon-Ja and symbolizing hope for their future.
