Let's start with ぐすん (gusun), which also describes crying. Gusun suggests a sudden, sharp intake of breath as tears well up. Think of a child who stubs their toe and lets out a quick "Gusun!" before the tears really start. Mesomeso, by contrast, describes a protracted, drawn-out weeping.

Mesomeso (メソメソ) is a Japanese onomatopoeia for a prolonged, quiet form of crying: sobbing, weeping, or whimpering. It describes a slow, persistent release of tears, often accompanied by a quiet, sniffling sound. Its emotional core is sadness and vulnerability, perhaps stemming from loneliness or disappointment. The focus is on the steady flow of tears and the person’s subdued emotional state.

Consider two scenarios:

Scenario 1: Kenta, a junior high student, is heartbroken because his dog, Tama, has run away. He searches for Tama everywhere, posting flyers. While searching, he sits on a park bench, shoulders slumped, tears silently tracking down his cheeks. He sniffles quietly, wiping his eyes with his sleeve. Here, mesomeso fits perfectly. It describes his extended sadness and quiet despair. The image is of a person consumed by loss, unable to stop the flow of tears.

Scenario 2: Akari, a high school student, is angry at her friend. They had a huge fight, and Akari is overwhelmed. She storms off, slamming the door. Alone in her room, she clenches her fists, shouting "I hate you!" and "It's so unfair!" before bursting into angry sobs. In this case, mesomeso would be less accurate. Here, the situation calls for a different onomatopoeia entirely.

Now, let's explore some nuanced alternatives. The word わんわん (wanwan) means a loud, unrestrained crying. This is the sound of loud wailing. It would be appropriate when a child is throwing a tantrum and crying loudly. In Akari's case, after slamming the door, she might begin wanwan. Mesomeso indicates an inward, tender, vulnerable state, while wanwan signifies an outward, dramatic display.

Another option is しくしく (shikushiku), which suggests quiet weeping, often with a hint of pain or regret. The crying is not as loud as wanwan, nor as drawn-out as mesomeso. This might depict a sense of deep personal sorrow. For example, if Kenta's parents tell him that they can’t afford to replace Tama, he might begin to cry shikushiku. Shikushiku emphasizes the individual’s sadness and the sting of their loss.

To summarize, mesomeso is a poignant choice for portraying a character’s subdued, sustained sorrow. Use it when the core emotion is quiet anguish and the tears flow steadily, yet not with the fury of wanwan or the sharp sting of shikushiku.