The first language (L1) use is vital to developing the quality of second-language (L2) writings. Establishing a clear argument with the logical flow in L2 can be a daunting task for learners with low L2 proficiency. To determine if L1 use is positively related to students' L2 texts, the researcher conducted a comparative study with 77 Japanese L2 learners. It examines differences amongst L2 argumentative essays resulting from four writing processes. The participants were divided into two focused groups, the experimental group formulating L1 texts and then translating into L2, and the contrast group composing texts directly in L2. Then, each group was divided into two sub-groups: One composing their texts using a writing framework, and the other with no framework. Over three L2 classes, each group experienced the writing process respectively. They submitted the essays before and after the processes. Two experienced L2 instructors assessed students' pre- and post-texts, and compared the texts of each group cross-sectionally and longitudinally. The results show that participants in the experimental group with the framework significantly improved their L2 text quality. Thus, the teaching of argumentative writing should incorporate the process of L1 formulation with a framework into a process-focused approach to efficiently facilitate students' L2 writing.