Is it acceptable to conduct interviews and company presentations in Japanese only?

Yes, it is perfectly acceptable to conduct company presentations and interviews in Japanese only.

Many candidates possess Japanese language skills at or above the level of everyday conversation. For Specified Skilled Workers,
the general guideline is a Japanese Language Proficiency Test (JLPT) level N4 or higher.

[Guidelines for Japanese Comprehension During Interviews]
While Japanese proficiency varies by individual, most candidates can generally handle the following:
・Self-introductions and explanations of their motivation for applying
・Explanations of their work history
・Understanding basic job duties
・Simple Q&A sessions
In many cases, communication is fully possible if you explain things slowly and concisely.

[Support as Needed]
If you are concerned about whether your message is being conveyed clearly or worried about the use of technical terms, we can provide the following support depending on the situation:
・Having an interpreter present
・Sharing the list of questions in advance
・Providing supplementary explanations after the interview
The interview will be conducted entirely in Japanese, and we will provide support whenever necessary.

At CROSSY GLOBAL.biz, we assess candidates' Japanese proficiency and communication skills through a preliminary interview before introducing them, ensuring they can understand instructions and perform effectively in the workplace.