CONCURRING OPINION OF
NAKAMURA, J.I concur in the court’s decision to set aside the judgment of conviction entered by the trial court But I write separately to set forth my reservations on the discussion of the law governing the admission of testimony related to other crimes, wrongs, and acts committed by the defendant in complicity with Thomas Guzzetta and testimony related to “Operation Rabbit”
I.
The cornerstone of the system of rational proof embodied in the Hawaii Rules of Evidence (Haw. R. Evid.), Hawaii Revised Statutes (HRS) § 626-1, is the concept of relevance. “Relevant evidence” is defined by Haw. R. Evid 401 as “evidence having any tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence.” By virtue of Haw. R. Evid. 402, “[a]ll relevant evidence is admissible, except as otherwise provided by the Constitutions of the United States and the State of Hawaii, by statute, by [the Hawaii Rules of Evidence], or by other rules adopted by the supreme court.” Irrelevant evidence, of course, “is not admissible.” Haw. R. Evid. 402. Under the system of rational proof adopted by the legislature,
[t]he determination of relevance is the process of determining whether the inference from [the proffered] facts to the material facts in the case is a permissible one. If so, the evidence comes in and the jury decides whether or not to draw the inference. If the court thinks the inference is improper, the evidence is excluded.
C. Wright & K. Graham, Federal Practice and Procedure: Evidence § 5162, at 17 (1978).
*311II.
The testimony about the defendant’s prior involvement in drug trafficking, I agree, was relevant and admissible. The court justifies its admission on these grounds:
Here, the identity of Guzzetta’s drug supplier was in dispute, and Austin had denied any involvement in the cocaine trafficking at issue. Austin’s past pattern of drug dealing with Guzzetta plus earlier trips to California to obtain cocaine is therefore probative of whether he had acted in complicity with Guzzetta in the instant action. See State v. Prince, 67 Haw. 231, 683 P.2d 1217 (1984). In short, State’s evidence rebuts Austin’s defense that he had not planned the crime where he had no cocaine when arrested. See State v. Reyes, 66 Haw. 613, 670 P.2d 1282 (1983) (per curiam).
As the opinion states, the testimony undoubtedly tended to establish the identity of the defendant as the supplier of the seized drug as well as the scheme of the defendant and Guzzetta to promote its sale. Thus, the testimony was admissible under Haw. R. Evid 404(b) as evidence of other crimes, wrongs, or acts “probative of. . . plan, knowledge, [and] identity,” not as an exception to the general rule of inadmissibility of character evidence under Haw. R. Evid. 404(a).
In discussing the law, however, the court appears to ascribe the admissibility of Guzzetta’s testimony to Haw. R. Evid. 404(a) by stating:
Although the trial court generally has the wide discretion to admit evidence, Hawaii Rules of Evidence (HRE) Rules 403 plus 404 specifically prohibit the introduction of prejudicial character evidence unless 1) an exception applies; and 2) there exists no other way to prove the accused’s guilt. See State v. Castro, 69 Haw. _, 756 P.2d 1033 (1988).
(Footnote omitted). It also appears to lay down a hard and fast rule of admissibility premised on the absence of other evidence to establish the defendant’s guilt I do not believe this aspect of the opinion accurately reflects the rule governing the admissibility of evidence of other crimes, wrongs, and acts.
“Haw. R. Evid. 404(b)... reiterates the common law rule ‘that the prosecution may not introduce evidence of other criminal acts of the accused unless the evidence is introduced for some purpose other than to *312suggest that because the defendant is a person of criminal character, it is more probable that he committed the crime for which he is on trial.’” State v. Castro, 69 Haw. at _, 756 P.2d at 1041 (citations omitted).
But even when such evidence tends to establish a fact of consequence to the determination of the case, the trial court cannot admit the evidence “if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence.” Haw. R. Evid. 403. In other words, the admissibility of the evidence even after a demonstration of relevance is a matter of discretion. And,
[i]n deciding whether the danger of unfair prejudice and the like substantially outweighs the incremental probative value, a variety of matters must be considered, including the strength of the evidence as to the commission of the other crime, the similarities between the crimes, the interval of time that has elapsed between the crimes, the need for the evidence, the efficacy of alternative proof, and the degree to which the evidence probably will rouse the jury to overmastering hostility.
E.W. Cleary, McCormick on Evidence § 190, at 565 (3d ed. 1984) (footnote omitted). The “need for the evidence” is but one of the factors a trial court must consider in weighing probative value against unfair prejudice pursuant to Haw. R. Evid. 403. The rule calling for a weighing of factors furnishes no basis for fashioning a subsidiary rule of admissibility based solely on the “need for the evidence.”
III.
In discussing the repeated references to “Operation Rabbit,” the opinion states “this court must determine if the trial court abused its discretion in balancing the relevance of the controverted evidence against the adverse effect to [the defendant] pursuant to HRE Rule 403.” It goes on to say “[t]he testimony regarding Operation Rabbit was somewhat relevant to outline how the police received information about the incriminating statements of [the defendant].” The record, however, does not bear this out; it confirms instead that the proffered evidence was irrelevant.
In considering the defendant’s motion to strike the testimony describing the “sting” operation, the trial court observed there wasn’t a *313“shred of evidence” implicating the defendant therein. But the court nevertheless denied the motion, stating:
There are shreds of evidence connecting it to people in this case but certainly not your client, therefore under [Hawaii Rules of Evidence] Rule 403, balancing the prejudice against the relevance, I’m going to deny your motion.
If, as the trial judge found, there was no shred of evidence connecting the defendant and Operation Rabbit, testimony about it was irrelevant; “there [was] no room for ad hoc balancing. The evidence [was] then unequivocally inadmissible[.]” E.W. Cleary, supra, at 565. For it had no rational “tendency to make the existence of any fact that [was] of consequence to the determination of the action more probable or less probable than it would [have been] without the evidence.” Haw. R.Evid.401. Of course,. it could have had an irrational and improper tendency to do so, as the opinion implies; but it is a system of rational proof we are expounding.